PROPOSED
STUDY
USING
OF....:. THE
CAKBON-14
GYGLOPEHTADIEEYL ANION
AS
A
TRACER,
by
RUSSELL
TKACHUK
A THESIS SUBMITTED I N PARTIAL FIILFLLMEM OF
THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
i n t h e Department
of
CHEMISTRY
We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o
the standards r e q u i r e d from candidates
f o r t h e degree o f MASTER OF SCIENCE
Members o f t h e department o f
Chemistry
THE
UNIVERSITY
OF
BRITISH COLUMBIA
A p r i l , 1956
ABSTRACT
I t i s thought t h a t some i n f o r m a t i o n about t h e bond
s t r u c t u r e i n t h e c y c l o p e n t a d i e n y l a n i o n can be p r o v i d e d b y
s y n t h e s i z i n g c y c l o p e n t a d i e n e - 5 - C ^ , making t h e c y c l o p e n t a d i e n y l a n i o n ( a s t h e p o t a s s i u m s a l t ) , and d e g r a d i n g
t h e c y c l o p e n t a d i e n e r e g e n e r a t e d from t h i s a n i o n f o r t h e
d e t e r m i n a t i o n o f t h e d i s t r i b u t i o n o f carbon-14:
DEGRADATION
A method f o r t h e s y n t h e s i s o f c y c l o p e n t a d i e n e , s t a r t i n g
f r o m formaldehyde,
h a s been shown.
p e n t a d i e n y l s a l t was t h e n made.
The p o t a s s i u m
cyclo-
The c y c l o p e n t a d i e n e
r e g e n e r a t e d from t h i s s a l t was c o m p l e t e l y degraded.
i t i o n o f t h i s work, u s i n g f o r m a l d e h y d e - C ^
Repet-
would g i v e t h e
desired cyclopentadiene-5-C^, e t c .
U s i n g carbon-14,
the precursor t o cyclopentadiene-5-G^
was made, b u t t h e s y n t h e s i s o f c y c l o p e n t a d i e n e - 5 - C ^
not be c a r r i e d
out i n t h e a v a i l a b l e t i m e .
could
ACKN0TO5DGMEHT
The a u t h o r w i s h e s t o express h i s a p p r e c i a t i o n o f t h e
encouragement, a d v i c e , and a s s i s t a n c e g i v e n b y D r . C. G.
Lee d u r i n g t h e c o u r s e o f t h i s
research.
TABLE OF CONTENTS
General I n t r o d u c t i o n - - - - - - - - - - -
1
Historical Introduction
A.
General
. 2
B.
The C y c l o p e n t a d i e n y l A n i o n
7
Discussion
A.
Synthesis of Cyclopentadiene
- - - -
B.
S y n t h e t i c and D e g r a d a t i v e P r o c e d u r e s
10
14
Experimental
A.
S o l v e n t s and Reagents
B.
S y n t h e t i c and D e g r a d a t i v e P r o c e d u r e s
Bibliography
- - - - - - -
- - - - - - - - - - - - - - -
19
21
38
GENERAL INTRODUCTION
The o b j e c t o f t h i s work i s a proposed
study o f t h e
bond-structure of the cyclopentadienyl anion.
The p r e s e n t
theory of "aromatic c h a r a c t e r " a s c r i b e s the s t a b i l i t y of arom a t i c compounds, o f w h i c h t h e c y c l o p e n t a d i e n y l a n i o n i s a
member, t o t h o s e u n s a t u r a t e d c o n j u g a t e d c y c l i c systems h a v i n g
six resonating TT-electrons.
I n the cyclopentadienyl anion,
t h e s e . c o n d i t i o n s a r e f u l f i l l e d by u t i l i z i n g t h e two e l e c t r o n s
w h i c h f o r m e r l y h e l d a carbon-hydrogen bond t o g e t h e r i n t h e
methylene group o f c y c l o p e n t a d i e n e :
He—CH
II
II
HC
H __ H
HC-—CM
+K°.
//
C
w
OH
8
C
/• — 1}
H
H
However, e x p e r i m e n t a l v e r i f i c a t i o n o f t h e s e p r e d i c a t i o n s i s
incomplete.
I t i s thought
that t h i s v e r i f i c a t i o n ,
or other-
w i s e , c a n be o b t a i n e d i n t h e case o f t h e c y c l o p e n t a d i e n y l a n i o n ,
by t h e use o f carbon-14- as a t r a c e r .
s y n t h e s i z i n g cyclopentadiene-5-C^- ,
4
T h i s c a n be done by
making t h e p o t a s s i u m
and t h e n r e g e n e r a t i n g c y c l o p e n t a d i e n e from t h i s l a t t e r
anion,
salt*
DEGRADATION
2.
I f the anion i s aromatic according t o our present d e f i n i t i o n
of
a r o m a t i c i t y , t h e n t h e carbon-14 i n t h e r e g e n e r a t e d
cyclo-
pentadiene w i l l be d i s t r i b u t e d e q u a l l y on e v e r y carbon atom.
I f t h e n e g a t i v e charge remains on t h e former methylene group,
the o r i g i n a l c y c l o p e n t a d i e n e - 5 - c l "
w i l l be r e g e n e r a t e d , e t c .
4
The aim i n t h e p r e s e n t work was t o f i n d a s u i t a b l e
h y p o t h e t i c a l synthesis f o r cyclopentadiene-5-C ",
14
for
and a method
t h e r e g e n e r a t i o n o f c y c l o p e n t a d i e n e from i t s p o t a s s i u m
salt.
T h i s was done.
To f a m i l i a r i z e o n e s e l f w i t h t h e r e a c t i o n
procedures and t o l e a r n t h e o v e r - a l l y i e l d , a
complete
s y n t h e s i s , f o r m a t i o n o f t h e p o t a s s i u m s a l t , r e g e n e r a t i o n , and a
complete d e g r a d a t i o n o f c y c l o p e n t a d i e n e were e f f e c t e d .
Time
p e r m i t t i n g , t h e above work was t o be r e p e a t e d as f a r as p o s s i b l e ,
u s i n g carbon-14.
C y c l o p e n t a n e - l , 2 - d i o l - 5 - C - ( c i s - t r a n s ) was
14
s y n t h e s i z e d , but the d e h y d r a t i o n o f i t t o cyclopentadiene c o u l d
not be r e p e a t e d .
HISTORICAL INTRODUCTION
(A)
GENERAL
A r o m a t i c compounds were so c l a s s i f i e d
because o f t h e i r odor.
originally
Today a r o m a t i c i t y o r a r o m a t i c c h a r a c t e r
i n f e r s a much d i f f e r e n t meaning.
A l t h o u g h t h e r e i s much d i s -
agreement on t h e d e f i n i t i o n o f a r o m a t i c i t y , v e r y b r i e f l y i t may
be a s s o c i a t e d w i t h c y c l i c compounds p o s s e s s i n g t h e f o l l o w i n g
properties:
(1) A v e r y s t a b l e n u c l e u s o f carbon atoms
(2)
A p a r t i c u l a r l y r e s i s t a n t t y p e o f u n s a t u r a t i o n towards
the f o r m a t i o n o f a d d i t i o n a l p r o d u c t s
(3)
A tendency t o undergo s u b s t i t u t i o n r e a c t i o n s
(4)
A c i d i c e n o l i c d e r i v a t i v e s w i t h l i t t l e tendency t o form
the " k e t o form"
(5)
A tendency t o form quinone and d i a z o n i u m s a l t s
(6) H a l i d e d e r i v a t i v e s w h i c h a r e v e r y i n e r t
(7)
A pronounced tendency towards t h e i r f o r m a t i o n .
Benzene and i t s d e r i v a t i v e s o f c o u r s e p r o v i d e t h e c l a s s i c a l
example o f i l l u s t r a t i n g t h e s e p r o p e r t i e s .
Chemists e l u c i d a t i n g t h e p r o p e r t i e s and s t r u c t u r e s
o f t h e s e a r o m a t i c compounds have come up w i t h many t h e o r i e s .
One s c h o o l o f t h o u g h t , due t o Armstrong, v o n Baeyer and
Bamberger, suggested t h a t a r o m a t i c c h a r a c t e r was due t o t h e
s y m m e t r i c a l arrangement o f c o n j u g a t e d l i n k a g e s i n t h e s e c y c l i c
compounds.
I n d e p e n d e n t l y , Armstrong (3)
i n 1888
i n 1887
and von Baeyer
(4)
p r o v i d e d f o r benzene a symbol based on t h e 2 4 - a f f i n i t i e s
o f t h e s i x c a r b o n atoms.
Of t h e s e 2 4 - a f f i n i t i e s , 12 a r e engaged
i n t h e f o r m a t i o n of t h e s i x - c a r b o n r i n g and s i x r e t a i n i n g t h e
s i x hydrogen atoms, w h i l e t h e r e m a i n i n g s i x r e a c t upon each
o t h e r — " a c t i n g towards a c e n t r e as i t w e r e " — s o
that the
" A f f i n i t y " m a y be s a i d t o be u n i f o r m l y and s y m m e t r i c a l l y
distributed
(3):
H
C
/ \
M
C
/ \
4
Bamberger ( 6 ) ,
in
1891-1893, suggested t h a t t h e s i x
v a l e n c e s unnecessary f o r t h e f o r m a t i o n o f benzene " s a t u r a t e d
each o t h e r " .
R i n g s n o t h a v i n g s i x such v a l e n c e s c o u l d n o t
a t t a i n the same s t a b i l i t y .
Bamberger extended h i s h e x a c e n t r i c
argument t o u n s a t u r a t e d h e t e r o c y c l i c s by u t i l i z i n g the s a l t
f o r m i n g v a l e n c e s o f the hetero-atoms:
0 5 P 5
Pyridine
Pyrrole
T h i e l e (53)
Thiophene
i n 1899,
Pyrazole(Imidazole)
Q
Furan
c o n s i d e r e d t h a t each c a r b o n atom
o f a double-bond t o possess a p a r t i a l v a l e n c e , and t h a t i n a
d i e n e t h e s e p a r t i a l v a l e n c e s n e u t r a l i z e each o t h e r w i t h t h e r e s u l t i n g a c c u m u l a t i o n o f r e s i d u a l energy a t the ends o f t h e
c o n j u g a t e d system (t© e x p l a i n 1 , 4 - a d d i t i o n s ) :
I
•
A p p l y i n g t h i s argument t o 4ke
—
"
I
I
Kekules cyclohexatriene formula
f o r benzene w i t h i t s c l o s e d c o n j u g a t e d system, t h r e e i n a c t i v e
double bonds a l t e r n a t i n g w i t h t h e o r i g i n a l / , d e a c t i v a t e d d o u b l e
bonds a r e formed, r e s u l t i n g i n s i x n e a r l y e q u i v a l e n t i n e r t
linkages:
5
I n the n i n e t e e n t h c e n t u r y , t h e v a l e n c e bond
was
r e p r e s e n t e d by a l i n e drawn between t h e symbols of two
elements,
the n a t u r e o f the bond b e i n g unknown.
chemical
F o l l o w i n g the
d i s c o v e r y o f t h e e l e c t r o n i n 1897• e l e c t r o n s i n s t e a d o f t h e
former l i n e s soon appeared as the l i n k between atoms i n c h e m i c a l
compounds.
not u n t i l 1 9 1 6 ,
However, i t was
when G. N. L e w i s
(40)
f o r m u l a t e d t h e b a s i s o f the modern e l e c t r o n i c t h e o r y o f v a l e n c e .
And
so e l e c t r o n i c f o r m u l a e f o r benzene soon appeared i n t h e
H
literature:
H--c
*
'C-.H
H
, „
.-. -H
> c
C
C •
M
The f i r s t a l t e r n a t i v e f o r m u l a t i o n f o r benzene, where
a l l the n u c l e a r c a r b o n atoms a r e connected
was
suggested
by t h r e e e l e c t r o n s ,
by Kauffmann(37)» and drawn by Kermac and
R o b i n s o n (39)«
H
ri-c
...
. c .
' c*u
•••
%
*C '
H
L a t e r , A r m i t and R o b i n s o n ( 2 )
suggested
t h a t the "aromatic s e x t e t "
i n t h e b e n z o i d group i n f e r s marked s t a b i l i t y and p o s t u l a t e d t h a t
groups o f two o r f o u r e l e c t r o n s a l s o o c c u r , f o r example, i n a c i d s
and c y c l o p e n t a d i e n e .
Gross and I n g o l d (28)
extended Bamberger's
t h e o r y by a s s i g n i n g e l e c t r o n i c s t r u c t u r e s t o t h e
h e t e r o - c y c l i c compounds:
aromatic
««
H
Pyrrole - ( b )
P y r r o l e - (a)
The second f o r m u l a
( b ) , again gives r i s e t o the aromatic
The a r o m a t i c
s i n c e Huckel(39) i n
sextet.
s e x t e t t h e o r y has r e c e i v e d much a t t e n t i o n
1931 i n v e n t e d
t h e quantum m e c h a n i c a l f o u n -
d a t i o n i n w h i c h he a s c r i b e s t h a t a r o m a t i c
character with i t s
r e l a t i v e s t a b i l i t y , o r i g i n a t e s f r o m those c o n j u g a t e d
unsaturated
cycles containing s i x i r - electrons.
The f i r s t a t t e m p t s t o t e s t t h i s a r o m a t i c
sextet
weweby W i l l s t a t t e r on t h e n o n - e x i s t e n t c y c l o b u t a d i e n e
theory
(63) and
cyclo—octatetraene(62,69)? w h i c h t h e o r e t i c a l l y a r e n o n - a r o m a t i c
molecules.
Cyclobutadiene
s t i l l has n o t been s y n t h e s i z e d and
w o u l d , i n any c a s e , have a l a r g e o b s c u r i n g a n g u l a r
strain.
C y c l o - o c t a t e t r a e n e , a l t h o u g h s y n t h e s i z e d , has a n o n - p l a n e r
s t r u c t u r e and so i s " I m p e r t i n e n t t o t h e theory(38).
predictions.^ concerning
definite
t h e f i v e and s even-member ed r i n g s a r e
(26,34,59)•(CH)5
s h o u l d be more s t a b l e t h a n (CH)y, and
(CH)£ s h o u l d be more s t a b l e t h a n ( C H ) ^ i
has n e v e r been p r e p a r e d ;
Theoretical
The p o s i t i v e i o n (CH)"£
but from the f a i l u r e o f c y c l o p e n t a -
dienone t o e x i s t as c o n t r a s t e d w i t h t h e s t a b i l i t y and b a s i c i t y
o f c y c l o h e p t a t r i e n o n e , i t c a n be i n f e r r e d t h a t t h e (CH) + i o n i s
much more s t a b l e t h a n t h e (CH)£ i o n
(15.20).
In
1954-,
D o e r i n g and Kn©x s y n e t h e s i z e d t h e c y c l o -
heptatrienylium (tropylium) i o n (21).
From i t s p r o p e r t i e s i t appears t h a t resonance
stabilization
i n t h e c y c l i c i o n i s l a r g e enough t o overcome t h e normal
tendency ©f t h e carbon-bromine bond t© be c o v a l e n t .
Thus we
have a n o t h e r new a r o m a t i c system i n w h i c h l a r g e resonance
energy o r i g i n a t e s f r o m t h e c y c l i c n a t u r e ©f t h e system.
I n summary t h e p r e s e n t " a r o m a t i c s e x t e t " t h e o r y
p r e d i c t s t h a t t h e c y c l e p e n t a d i e n y l i o n , benzene and t h e
cycloheptatrienylium i o n
c o n s t i t u t e a t r i a d p o s s e s s i n g a r o m a t i c resonance energy and
hence r e m a r k a b l e s t a b i l i t y .
(B)
THE CYCLOPENTADIENYL ANION
The resonance energy ©f c y c l o p e n t a d i e n e , c a l c u l a t e d
f r o m t h e h e a t ©f h y d r o g e n a t i o n , i s o n l y about 3 k c a l / m o l e
(5).
But c y c l o p e n t a d i e n e p o s s e s s e s an a c t i v e methylene group, and
has an e x c e p t i o n a l l y h i g h a c i d i t y f o r a h y d r o c a r b o n , as
8.
potassium t-butoxide (pK^ 19) converts cyclopentadiene
quantitatively into i t s potassium s a l t ( 4 9 ) .
This shows that
the negatively charged i o n
Is very stable, although very reactive chemically.
The
reason given by Goss and Ingold (28) i n 1928, was that t h i s
ion had s i x *7T -electrons d i s t r i b u t e d over f i v e equivalent CH
groups, thus constituting a stable aromatic system s i m i l a r to
benzene.
The resonance energy of the Ion has been calculated
to be about 42 kcal./mole, and apparently i s i n harmony with
the observed s t a b i l i t y (48).
The tendency of the cyclo-
pentadiene system to accept an electron and thus achieve
aromatic s t a b i l i t y i s also shown by the fulvenes.
Dimethylfulven (R-RlnMe) has a dipole moment of 1.44D, the
r i n g being negative and the carbon atom-6 positive(60).
This
indicates the electron a t t r a c t i n g nature of the ring which
tends to acquire a stable sextet of electrons.
The recently
prepared diazocyclopentadiene (19)
i s a very stable molecule.
I t i s suggested that the molecule
i s a resonance hybrid of the two following structures:
9.
0
fu-
ll
N +
\\\
N
N -
The
f©rm i n w h i c h t h e r i n g accommodates t h e n e g a t i v e
charge
pr©bably c o n t r i b u t e s most t© t h e h y b r i d .
The
aromatic
character of the
cyclopentadienium
r i n g i s b e s t i l l u s t r a t e d by dicycl©pentadienyl ir©n ( 5 ) *
T h i s compound i s i n s o l u b l e i n , and does n o t r e a c t w i t h w a t e r ,
sodium h y d r o x i d e ,
©r cone, h y d r o c h l o r i c a c i d .
composed a t 470®.
known.
I t i s n e t de-
The e x a c t n a t u r e o f t h e Fe-C bonds i s n o t
Regarding the c y c l o p e n t a d i e n y l r i n g s , i n f r a r e d
spectrum i n d i c a t e s o n l y one t y p e ©f C-H bond, and X - r a y
e v i d e n c e i n d i c a t e s t h a t t h e five-membered r i n g s a r e p l a n a r ,
and s y m m e t r i c a l ,
t h e C-C d i s t a n c e s b e i n g about 1*4 A.
D i c y c l o p e n t a d i e n y l i r o n does n o t r e a c t w i t h m a l e i c
anhydride,
cannot be c a t a l y t i c a l l y h y d r o g e n a t e d , and undergoes t h e
Friedel-Crafts reaction.
Because o f t h e s e t y p i c a l l y
aromatic
c h a r a c t e r i s t i c s , t h e compound has been named f e r r o c e n e .
10.
The
only experimental
work on t h e s t r u c t u r e o f
c y c l o p e n t a d i e n y l a n i o n seems t o be t h a t by A l d e r and
r i c h t e r ( 1 ) , who
t r e a t e d the potassium s a l t of
the
Holz-
cyclopentadiene
w i t h b e n z y l c h l o r i d e and o b t a i n e d b o t h b e n z y l - and d i b e n z y l cyclopentadienes
the 1-and
and t h e i r d i m e r s .
2-benzyl cyclopentadienes
From t h e s e p r o d u c t s
were f o u n d .
S t r a n g e l y , t h e !ir b e n z y l d e r i v a t i v e was
not formed.
T h i s work
i s l i m i t e d i n t h a t one does not know whether o r not t h e
p o l y m e r i z a t i o n ©f d i c y c l o p e n t a d i e n e
tautomeric
changes.
Besides
de-
derivatives involves
the f a c t t h a t the 5-benzyl
v a t i v e d i d not f o r m , t h e a u t h o r s
only
c o u l d not add any
t o the s t r u c t u r e of the c y c l o p e n t a d i e n y l
deri-
information
anion.
DISCUSSION
(A)
The
SYNTHESIS OF CYCLOPENTADIENE
immediate p r e c u r s o r t o c y c l o p e n t a d i e n e ,
labelled
i n t h e methylene group w i t h carbon-14
was
chosen t o be ( c i s - t r a n s ) c y c l o p e n t a n e - l - d i o l - 4 - C ^ s i n c e
i t was
shown i n the p r e s e n t work t h a t c y c l o p e n t a d i e n e
could
11.
be p r e p a r e d from t r a n s - c y c l o p e n t a n e - l , 2 - d i o l i n a y i e l d o f 2 0 $ :
CC -«-a
Whether t h e d e h y d r a t i o n does proceed as shown above c a n o n l y be
determined
by an a c t u a l d e h y d r a t i o n . a t t e m p t
* cyclopentane-l,2-^iol-4-C
1 4
of (cis-trans)
f o l l o w e d by d e g r a d a t i o n o f t h e
cyclopentadiene obtained to a s c e r t a i n the l o c a t i o n of C
1 4
in
the r i n g .
I f t h e d e h y d r a t i o n , as shown i n t h e p r e c e d i n g
paragraph, was n o t s u c c e s s f u l , we s t i l l have two o t h e r p o s s i b i l i t i e s o f o b t a i n i n g c y c l o p e n t a d i e n e from ( c i s - t r a n s ) c y c l o p e n t a n e - l , 2 - d i o l - 4 - C - , o r from i t s p r e c u r s o r ,
1 4
dione-4-C - .
3
4-
One p o s s i b i l i t y would be a
1,2-cyclopenta-
dehydrohalogenation
of l ^ - d i b r o m o c y c l o p e n t a n e ^ - c l " according to the f o l l o w i n g
4
scheme:
<z - cc - cc
o
The d i a c e t a t e o f c y c l o p e n t a n e - l , 2 d i o l has been p r e p a r e d ( 4 1 ) ,
and t h e two r e m a i n i n g s t e p s a r e s i m i l a r t o t h e s u c c e s s f u l
preparation of 1,3-cyclohexadiene
(65).
Furthermore,
a
s i m i l a r p r e p a r a t i o n has been s u c c e s s f u l i n t h e p r e p a r a t i o n o f
c y c l o h e p t a t r i e n e by W i l l s t a t t e r ( 6 l ) .
The second p o s s i b i l i t y would be t h e p r e p a r a t i o n o f
the d i o x i m e and t h e n t h e diamine from
l,2-cyclopentadione-4
w h i c h has been r e a l i z e d by Jaeger and Blumendal ( 3 5 ) :
12.
=N-OH
=N-OH
From t h e d i a m i n e , a Hoffmann d e g r a d a t i o n c o u l d be a t t e m p t e d
as i n t h e attempted
s y n t h e s i s o f c y c l o b u t a d i e n e by Buchman and
h i s c o l l a b o r a t o r s (10) o r t h e famous s y n t h e s i s o f c y e l o o c t a t e t r a e n e by W i l l s t a t t e r and co-workers ( 6 2 , 6 4 ) , and more
r e c e n t l y by Cope and O v e r b e r g e r ( 1 2 ) .
Besides the cleavage of d i c y c l o p e n t a d i e n e , there
seem t o be o n l y t h r e e r e p o r t e d r e a c t i o n s w h i c h l e a d t o
cyclopentadiene.
O n l y one o f t h e s e methods would be u s e f u l i n
t h i s p r e s e n t w o r k , namely, t h e h y d r o l y s i s o f t h e d i - p - t o l u e n e sulphonate o f cyclopentane-l,2-di©l
a c c o r d i n g t o Owen and
Smith(44).
The y i e l d o f c y c l o p e n t a d i e n e was n o t r e c o r d e d by Owen and S m i t h .
However, i n two a t t e m p t s t o r e p e a t t h e work o f t h e s e
no c y c l o p e n t a d i e n e c o u l d be d e t e c t e d .
authors,
13.
T h l e l e i n 1901 o b t a i n e d c y c l o p e n t a d i e n e by t h e
r e d u c t i o n o f 2,4-dibromo c y c l o p e n t e n e w i t h z i n c d u s t i n
glacial acetic acid
(55).
T h i e l e d i d not m e n t i o n t h e y i e l d , but f r o m h i s d e s c r i p t i o n
o f t h e r e a c t i o n , t h e y i e l d o f c y c l o p e n t a d i e n e seemed considerable.
However 2,4-dibromo-cyclopentene i s made f r o m
c y c l o p e n t a d i e n e , and t o s y n t h e s i z e
pentene-3
2,4-dibromo-l-cyclo-
seems a v e r y f o r m i d a b l e , i f not i m p o s s i b l e ,
task.
F i n a l l y , B r a u n and Kuhn have r e p o r t e d t h a t , d u r i n g the
p r e p a r a t i o n o f o - c y c l o p e n t e n y l p h e n o l , by condensing
sodium
p h e n o l a t e and 2 - c y c l o p e n t e n y l , ( 8 ) ,
an a l k a l i - i n s o l u b l e p o r t i o n o f the product was
obtained.
l a t t e r o i l , w i t h a b o i l i n g p o i n t o f 110-200° a t 12 mm.,
a d i s t i n c t odor o f c y c l o p e n t a d i e n e .
This
evolved
I t w o u l d seem t h a t t h i s
r e a c t i o n i s not v e r y s u i t a b l e f o r the p r e p a r a t i o n o f c y c l o p e n t a d i e n e l a b e l l e d i n t h e 5-
position.
14
(B)
SYNTHETIC AND DEGRADATIVE PROCEDURES
The
p r e l i m i n a r y s y n t h e t i c p r o c e d u r e s l i s t e d below
were donewithAview t £ p e r f e c t i n g a r o u t e f o r t h e f o r m a t i o n o f
14
cyclopentadiene-5-C
C r t l =
°
tooar
c«<coo£t),
coot*
The
:
C
0
C
H
C00£+
synthesis of cyclopentadiene
s t a r t e d from formaldehyde,
as e v e n t u a l l y t h e carbon-14 c o u l d t h e n be i n t r o d u c e d i n t h e
f o r m o f formaldehydeThus t e t r a e t h y l p r o p a n e - 1 , 1 , 3 , 3 * t e t r a c a r b o x y l a t e ( I )
was
p r e p a r e d from t h e c o n d e n s a t i o n
malonate and h y d r o l y z e d
o f formaldehyde and d i e t h y l
t o g l u t a r i c a c i d ( I I ) . This
a c i d was t h e n e s t e r i f i e d t o d i e t h y l g l u t a r g t e ( I I I ) .
Dieckmann c o n d e n s a t i o n
glutaric
A
o f t h e l a t t e r w i t h d i e t h y l o x a l a t e gave
3,5-dicarboethoxycyclopentadione-l,2(IV),
afforded cyclopentadione-l,2(V).
w h i c h on h y d r o l y s i s
H y d r o g e n a t i o n o f (V) o v e r
p l a t i n u m oxide, gave a p p a r e n t l y a n i s o m e r i c m i x t u r e o f ( c i s - t r a n s )
cyclopentane-l,2-diolsCVT).
As t h i s l a t t e r p r o d u c t c o u l d n o t
be c h a r a c t e r i z e d by o r d i n a r y means, a u t h e n t i c t r a n s - c y c l o pentane-l,2-diol(XXIII)
was s y n t h e s i z e d , s t a r t i n g from a d i p i c
a c i d as i n t h e f o l l o w i n g sequence:
ci ci a cr
oH
H
xtx
*x
xxi
xxn
xxti!
15.
Cyclopentanone(XX),
p r e p a r e d by h e a t i n g a d i p i c a c i d ( X I X ) w i t h
barium h y d r o x i d e , was c o n v e r t e d t o c y c l o p e n t a n o l ( X X I ) w i t h
l i t h i u m aluminum h y d r i d e .
w i t h 85$
Dehydration of the l a t t e r a l c o h o l
o r t h o - p h o s p h o r i c a c i d gave c y c l o p e n t e n e ( X X I I ) , w h i c h
i n t u r n was t r a n s - e s t e r i f i e d w i t h p e r f o r m i c a c i d and h y d r o l y z e d
to give trans-cyclopentane-l,2-diol(XXIII).
The o v e r - a l l
yield
•from a d i p i c a c i d was 1 9 . 5 $ .
A f t e r t h e t r a n s - c y c l o p e n t a n e - l , 2 - d i o l was c h a r a c t e r i z e d ,
an i n f r a r e d spectrum was t a k e n o f i t , and a l s o o f t h e c y c l o p e n t a n e - l , 2 - d i o l o b t a i n e d by h y d r o g e n a t i o n
2(V).
of
cyclopentadione-1,
The i n f r a r e d a b s o r p t i o n c u r v e s o b t a i n e d f o r t h e s e two
a l c o h o l s , as 3% s o l u t i o n s i n c h l o r o f o r m , were
superimposable
except f o r one e x t r a s l i g h t peak i n t h e " f i n g e r - p r i n t " r e g i o n
f o r t h e d i o l ( V I ) from t h e h y d r o g e n a t i o n o f V. ( F i g . 1, p. 37)
C y c l o p e n t a d i e n e ( V T I ) , i n a y i e l d o f 20$, was
prepared
by p a s s i n g t r a n s - c y c l o p e n t a n e - l , 2 - d i o l over a l u m i n a p e l l e t s a t
400°i
The c y c l o p e n t a d i e n e produced, b e s i d e s i t s v e r y
characteristic
odor, was c h a r a c t e r i z e d as t h e m a l e i c a n h y d r i d e adduct.
The
p r e p a r a t i o n o f c y c l o p e n t a d i e n e by t h i s method i s n o t l i s t e d i n
the l i t e r a t u r e .
Potassium
c y c l o p e n t a d i e n i d e ( I Q I I ) was made by r e a c t i n g
c y c l o p e n t a d i e n e w i t h m e t a l l i c p o t a s s i u m i n benzene and e t h e r .
16
By u s i n g t h i s m i x t u r e o f s o l v e n t s i n s t e a d o f benzene a l o n e ,
a p r o d u c t i s o b t a i n e d w h i c h i s more f i n e l y d i v i d e d and n o t
apt t o c o n t a i n v e r y s m a l l p i e c e s o f u n r e a c t e d p o t a s s i u m .
t h i s potassium-cyclopentadiene
as
If
s a l t does c o n t a i n m e t a l l i c
p o t a s s i u m , t h e n the next r e a c t i o n on t h i s s a l t would be v e r y
v i g o r o u s , and u s u a l l y would end i n a f i r e .
Regeneration of cyclopentadiene(IX), i n a y i e l d
43$,
was
of
a f f o r d e d by a d d i t i o n o f c o l d cone, h y d r o c h l o r i c a c i d :
I n f u t u r e work, p r o b a b l y h i g h e r y i e l d s o f c y c l o p e n t a d i e n e c o u l d
be o b t a i n e d by d i s s o l v i n g t h e p o t a s s i u m
s a l t i n tetrahydro.-->•
fiMfy and t h e n adding t h e t h e o r e t i c a l amount of hydrogen
c h l o r i d e gas.
T h i e l e (5^) mentioned t h a t c y c l o p e n t a d i e n e i s
regenerated from potassium
s a l t by t h e a d d i t i o n o f w a t e r .
R e p e t i t i o n o f T h i e l e ' s work r e s u l t e d i n a r e s i n f o r m a t i o n
t o g e t h e r w i t h a poor y i e l d o f c y c l o p e n t a d i e n e .
In this reaction
j H ) V <w—* (Tj
+K0H
the r e a c t i n g m i x t u r e becomes b a s i c as the r e a c t i o n p r o c e e d s .
Thus, p r o b a b l y , the c y c l o p e n t a d i e n e formed i s r a p i d l y p o l y m e r i z e d , as a c i d s and bases c a t a l y z e such p o l y m e r i z a t i o n .
17.
By a d a p t i n g former d e g r a d a t i o n s o f c i s - c y c l o p e n t a n e - 1 ,
2 - d i a m i n e ( 4 5 ) and s u c c i n i c a c i d ( 7 ) > the scheme f o r t h e
location
o f t h e c a r b o n - C l 4 i n t h e c y c l o p e n t a d i e n e samples i s a s f o l l o w s :
!£. .
COOH
**•
CM7
^
COOH
Z
*3_
xl
xm
coorle
COHHNHZ
cO/V*
I*.
->
cH
coort^
i«t
ctfi
^
CO/Vff-Jtff/i
CM, '
cHi
co/v\t
^
t
XV
XVI
The d i - e t h y l e s t e r o f
xv^l
xTy
CHa-**coo*
' cH,-NHcoo6t
^
XVIII
^
-
S
C
o
CH,. H
N
1
XIX
XX
2,3-diazabicycle(2.2.1)-!?-heptehe-2,
3 - d i e a r b o x y l i c a c i d ( X ) was o b t a i n e d by a D i e l s - A l d e r r e a c t i o n
between c y c l o p e n t a d i e n e and e t h y l a z o d i c a r b o x y l a t e .
Hydrogenation
o f the D i e l s - A l d e r adduct gave t h e d i e t h y l e s t e r
of 2 , 3 - d i a z a b i c y c l e ( 2 . 2 . 1 ) h e p t a n e - 2 , 3 - d i c a r b o x y l i c
acid(XI),
w h i c h , o n h y d r o l y s i s w i t h m e t h a n o l i c p o t a s s i u m h y d r o x i d e , gave
2,3-diazabicycle(2.2.1)
c h l o r i d e complex.
heptane ( X I I ) , i s o l a t e d as t h e cuprous
R e d u c t i o n o f X I I w i t h t i n and h y d r o c h l o r i c
a c i d gave c i s - c y c l o p e n t a n e - 1 , 3 - d i a m i n e ( X I I I ) , w h i c h was o x i d i z e d
w i t h n e u t r a l potassium
permanganate t o s u c c i n i c a c i d ( X I V ) .
U s i n g t h e C u r t i u s d e g r a d a t i o n method('3,l^), t h e s u c c i n i c
was
acid(XIV)
d e g r a d e d . I a l o n g the sequence o f the d i m e t h y l e s t e r ( X V )
dihydrazide(XVI) —
diazide(XXVII) ~
f i n a l l y t o ethylenediamine(XIX)
—
d i u r e t h a n ( X V I I I ) , and
and c a r b o n d i o x i d e ( X X ) . The
o v e r - a l l y i e l d o f ethylenediamine
f r o m c y c l o p e n t a d i e n e was 0,4$
18.
The l o c a t i o n o f t h e carbon-14 i n t h e
w o u l d , h y p o t h e t i c a l l y , be determined
cyclopentadiene
i n t h e f o l l o w i n g manner:
The d i f f e r e n c e between the m a l e i c a n h y d r i d e adduct o f c y c l o p e n t a d i e n e ( I X ) and the s u c c i n i c a c i d ( X I V ) w o u l d r e p r e s e n t t h e
a c t i v i t y o f the methylene group i n I X .
The
carbon d i o x i d e
produced i n the o x i d a t i o n o f X I I I cannot be used f o r t h e
measurement o f the a c t i v i t y o f the methylene group i n t h e
c y c l o p e n t a d i e n e ( I X ) because p o t a s s i u m permanganate o x i d a t i o n
o f c i s - c y c l o p e n t a n e - l , 3 - d i a m i n e ( X I I I ) would be expected
cleave other p a r t s of the r i n g .
As the 1,4-and
to
2,3-positions
a r e e q u i v a l e n t i n c y c l o p e n t a d i e n e , t h e n the d i f f e r e n c e i n
radioactivity
o f XIV and XIX would r e p r e s e n t t h e a c t i v i t i e s o f
the 1- and 4 - p o s i t i o n s o f I X .
The a c t i v i t y o f XX, i s o l a t e d
as
barium c a r b o n a t e , c o u l d be used as a check f o r t h e a c t i v i t y
of
the l $ 4 * p d s i t l g i i s . v *
XIX
F i n a l l y , measurement o f the a c t i v i t y ©f
would g i v e the a c t i v i t y of the 2 , 3 - p o s i t i o n s .
A check f©r
a c t i v i t y o f the methylene g r o u p , would be o b t a i n e d by
the
adding
the a c t i v i t i e s o f XIX and XX, and s u b t r a c t i n g t h i s v a l u e f r o m
the value obtained f o r IX.
The
above was
complete s y n t h e t i c and d e g r a d a t i o n r o u t e l i s t e d
done u s i n g " n o n - l a b e l l e d " compounds.
r e a c t i o n s were done a t l e a s t t w i c e .
work was
repeated to the
Most o f
th©
U s i n g carbon-14, the above
(cis-trans)cyclopentane-l,2-diol(VI).
A number o f a t t e m p t s were made i n t r y i n g t o s y n t h e s i z e
c y c l o p e n t a d i e n e - C " ; however t h e y a l l f a i l e d , and l a c k o f time
14
p r e v e n t e d any f u r t h e r r e s e a r c h .
19.
I n f u t u r e r e s e a r c h , more e x p e r i m e n t a l d e t a i l s on
the d e h y d r a t i o n o f ( c i s - t r a n s ) c y c l o p e n t a n e - l , 2 - d i o l
have t o
be o b t a i n e d f i r s t , b e f o r e t h e Cl4-phase o f t h e work c a n be
completed t o shed some l i g h t on t h e s t r u c t u r e o f t h e c y c l o pentadienyl anion.
EXPERIMENTAL (#)
A.
REAGENTS AND SOLVENTS
Chloroform
F o r i n f r a r e d measurements, r e a g e n t
grade
c h l o r o f o r m was shaken w i t h cone, s u l f u r i c a c i d , washed w i t h
sodium b i c a r b o n a t e s o l u t i o n and t h e n w i t h w a t e r .
3$
The r e s u l t i n g
c h l o r o f o r m was d r i e d f i r s t w i t h c a l c i u m c h l o r i d e , t h e n w i t h
c a l c i u m s u l f a t e , and f i n a l l y d i s t i l l e d .
The f r a c t i o n c o l l e c t e d
b o i l e d a t 6l° ( 2 4 ) .
Ethanol
F o r r e a c t i o n s i n v o l v i n g m e t a l l i c sodium,
t h i s r e a g e n t was made " a b s o l u t e " by t h e Lund and B j e r r u m
method ( 2 2 ) .
Ether
F o r r e a c t i o n s i n v o l v i n g m e t a l l i c sodium o r
p o t a s s i u m , commercial " a b s o l u t e " e t h e r was d r i e d over sodium
w i r e and t h e n d i s t i l l e d f r o m phosphorous p e n t o x i d e , b.p. 35°.
E t h y l Oxalate
Reagent grade as s u p p l i e d by Eastman
Kodak, was shaken w i t h 3% sodium b i c a r b o n a t e , washed w i t h
w a t e r , d r i e d w i t h c a l c i u m s u l f a t e and vacuum d i s t i l l e d a t
42-44° a t 0.6 mm.
(#) A l l m e l t i n g p o i n t s r e p o r t e d i n t h e p r e s e n t work,
were o b t a i n e d b y h e a t i n g a copper b l o c k c o n t a i n i n g t h e sample
and thermometer, and a r e u n c o r r e c t e d .
20.
Methanol
When " a b s o l u t e " methanol was needed,
commercial r e a g e n t grade methanol was d r i e d and p u r i f i e d by
t h e Lund and B j e r r u m method ( 2 3 ) .
P l a t i n u m Oxide
C a t a l y s t f o r h y d r o g e n a t i o n s , was
used as s u p p l i e d by B r i c k m a n and Company.
Alumina
Catalyst f o r dehydrations, i n p e l l e t s of
a p p r o x i m a t e l y 3 mm. i n d i a m e t e r , as s u p p l i e d by The Harshaw
C h e m i c a l Company.
Sodium E t h o x i d e
P r e p a r e d by a d d i n g f r e s h l y c u t
sodium t o an a p p r o x i m a t e l y t e n - f o l d e x c e s s o f " a b s o l u t e " e t h a n o l
i n a n i t r o g e n "dry-box".
A r e f l u x condenser was t h e n a t t a c h e d
t o t h e r e a c t i o n v e s s e l and under a slow stream o f d r y n i t r o g e n ,
t h e r e a c t i o n was a l l o w e d t o proceed a t room t e m p e r a t u r e .
A f t e r t h e r e a c t i o n was complete (approx. 24 h r s . ) t h e e x c e s s
e t h a n o l was removed a t t h e w a t e r pump.
To remove t h e a l c o h o l
c o m p l e t e l y , t h e sodium e t h o x i d e was d r i e d a t 1 0 0 °
f o r approximately four hours.
a t 0 . 1 mm.
C a r e f u l work w i l l r e s u l t i n a
p r o d u c t w h i c h i s easy t o powder, and w h i t e i n c o l o r .
p-Toluenesulfonvl Chloride
C. P. g r a d e , as s u p p l i e d
by Eastman Kodak, was p u r i f i e d by s h a k i n g a benzene s o l u t i o n
with %
sodium h y d r o x i d e , washing w i t h w a t e r and vacuum d i s -
tilling
(25).
had
a m.p.
The p r o d u c t w h i c h c r y s t a l l i z e d i n t h e r e c e i v e r ,
of 6 8 . 5 ° .
L i t . , 69°
(25).-
E t h y l h y d r a z o d i c a r b o x y l a t e P r e p a r e d f r o m 8$%
h y d r a z i n e h y d r a t e and e t h y l e h l o r o f o r m a t e ( 4 5 ) i n 8 3 $ y i e l d
w i t h a m.p. o f 1 2 7 . 5 - 1 3 0 ° .
L i t . 131° ( 4 5 )
21.
E t h y l A z o d i c a r b o x y l a t e P r e p a r e d by o x i d i z i n g e t h y l
h y d r a z o d i c a r b o x y l a t e w i t h c h l o r i n e gas(45 i n 57*2$ y i e l d .
The p r o d u c t , a b e a u t i f u l orange-red l i q u i d , b o i l e d a t 104° a t
11.0 mm.
L i t . 1 1 1 ° a t 15 mm.(45).
Nitrosomethylurea
P r e p a r e d by a d d i n g a 50$ sodium
n i t r i t e solution to a hot, p r e f i l t e r e d s o l u t i o n of
methylamine
h y d r o c h l o r i d e and p o t a s s i u m c y a n a t e , f o l l o w e d by t h e a d d i t i o n
o f c o l d 15$ s u l f u r i c a c i d t o t h i s s o l u t i o n a t -5 t o 0 ° (58).
The s l i g h t l y cream c o l o r e d c r y s t a l l i n e p r o d u c t was f i l t e r e d
o f f , t h o r o u g h l y washed w i t h water and d r i e d over phosphorous
p e n t o x i d e a t 0.5 mm. p r e s s u r e .
mately -15°»
The p r o d u c t s t o r e d a t a p p r o x i -
and p r o t e c t e d f r o m l i g h t , was s t i l l s t a b l e and
u s a b l e s i x months l a t e r .
B.
SYNTHETIC AND DEGRADATIVE PROCEDURES
Tetraethyl Propane—1.1.3.3-tetracarboxylate
( I ) (11)
To a m i x t u r e o f 320 gm. o f f r e s h l y r e d i s t i l l e d d i e t h y l
malonate
and 84 m l . o f 35$ f o r m a l d e h y d e , c o o l e d t o 2 ° i n a n
i c e - b a t h , was added 6.0 gm. o f p o t a s s i u m c h l o r i d e and t h e n
5.0 gm. o f f r e s h l y d i s t i l l e d d i e t h y l a m i n e .
The components were
w e l l shaken and t h e n a l l o w e d t o come t o room temperature and
thus kept f o r 16 hours w i t h o c c a s i o n a l s h a k i n g .
The r e a c t i o n
m i x t u r e was t h e n h e a t e d on a steam b a t h f o r s i x h o u r s , c o o l e d
t o room t e m p e r a t u r e , t h e w a t e r s e p a r a t e d o f f and t h e r e m a i n i n g
l i q u i d vacuum d i s t i l l e d .
The f r a c t i o n c o l l e c t e d b o i l e d a t
143-1460 a t 0.5 mm. and weighed 266.4 gm. (82.7$).
22.
Glutaric Acid (II) (11)
Into a three-necked f l a s k , f i t t e d with a r e f l u x
condenser, s t i r r e r and thermometer, was placed
tetraethyl propane-1,1,3,3-tetracarboxy.late
hydrochloric acid.
386.4 gm. of
and 78O ml. of
50$
With s t i r r i n g , the reaction mixture was
slowly refluxed u n t i l the mixture became homogenous (approx.
six hours).
The reaction mixture was then d i s t i l l e d under
reduced pressure u n t i l the water and hydrochloric acid were
removed.
As ©n cooling the material i n the d i s t i l l a t i o n f l a s k
did not s o l i d i f y , i t was further refluxed f o r two hours with
200 ml. of 50$
hydrochloric acid, and then the water and hydro-
c h l o r i c acid removed under reduced pressure.
gm.
On cooling,
(104.5$) of crude g l u t a r i c acid was obtained.
147.0
A small
portion r e c r y s t a l l i z e d twice from benzene, had a melting point
of 95-96°, L i t . 97°
(30).
A mixed m.p. with authentical, once
r e c r y s t a l l i z e d g l u t a r i c acid showed no depression.
E t h y l Glutarate (III) (42)
Into a one-liter d i s t i l l a t i o n f l a s k were placed
146.5
(1.11 moles) of crude g l u t a r i c acid, 400 ml. of absolute ethanol,
200 ml. of toluene and O.83
ml. of cone, s u l f u r i c a c i d .
The
f l a s k was connected to an ordinary d i s t i l l i n g apparatus and
heated u n t i l the azeotropic mixture of ethanol, toluene and
water began to d i s t i l at 75°.
the
D i s t i l l a t i o n was continued u n t i l
b.p. of the d i s t i l l a t e reached 78°.
The d i s t i l l a t e was
dried with 170 gm. of anhydrous potassium carbonate, f i l t e r e d
and returned to the d i s t i l l a t i o n f l a s k which was again heated
u n t i l the b.p. of the d i s t i l l a t e reached 80°.
At t h i s point
vacuum d i s t i l l a t i o n was
at
112-119°,
10-11
at
commenced.
The
product c o l l e c t e d b o i l e d
and weighed 124.0
mm.,
gm.
(59.6$).
I n o t h e r r u n e , when the g l u t a r i c a c i d used was
c r y s t a l l i z e d from benzene, a y i e l d of
was o b t a i n e d , b o i l i n g a t I 3 6 - I 3 7
20
N
D
0
88.6$
of e t h y l
a t 32 mm.,
1.4241; hp. 103-104° a t 7 mm.
gm.
(1.29
(30).
(17)
moles) of e t h a n o l - f r e e ,
sodium e t h o x i d e , c o v e r e d w i t h 500
glutarate
1.4234. L i t . ,
^-?-Dicarboeth©xycyclopentadione-1.2 (IV)
To 88.0
re-
white
m l . of anhydrous e t h e r ,
con-
t a i n e d i n a o n e - l i t r e round-bottomed f l a s k f i t t e d w i t h a r e f l u x
condenser,
o x a l a t e was
95.8
added.
orange c o l o r .
was
(O.656
gm.
Now
moles) o f f r e s h l y r e d i s t i l l e d
On m i x i n g t h i s t u r n e d i n t o a p a l e
123.4
(O.656
gm.
moles) of e t h y l
added d r o p w i s e over a p e r i o d o f 30 m i n u t e s , the
m i x t u r e deepening i n c o l o r d u r i n g t h i s a d d i t i o n .
was
yellowish-
glutarate
reaction
The
mixture
r e f l u x e d f o r one h o u r , the e t h e r d i s t i l l e d o f f , and
r e s i d u e heated to
125-130°
of 10$
T h i s r e s i d u e was
ground i n t o a
s l o w l y added t o a w e l l s t i r r e d i c e - c o l d s o l u t i o n
s u l f u r i c a c i d , whereupon the e s t e r p r e c i p i t a t e d out
a cream-colored s o l i d .
The
p r e c i p i t a t e was
r e c r y s t a l l i z e d from a p p r o x i m a t e l y 500
d r i e d c r y s t a l l i n e p r o d u c t w e i g h t was
of
115.5-116.5°•
of "near 118°,
gm.
and
ethanol.
(69*2$)
and had
The
a
A s m a l l p o r t i o n o f the e s t e r , r e c r y s t a l -
l i z e d once more, had a m.p.
a m.p.
m l . o f 95$
110
as
washed w i t h i c e -
c o l d w a t e r , f i l t e r e d , sucked d r y on the Buchner f u n n e l
m.p.
the
f o r f o u r h o u r s , when i t changed t o
a y e l l o w i s h - b r o w n , d r y cake.
f i n e powder and
ethyl
of 116-117°.
and a y i e l d o f 50$.
The
l i t e r a t u r e reports
(17)
24.
Cvclopentadione-1.2
(V) (31)
I n a o n e - l i t r e round-bottomed f l a s k equipped
with
a r e f l u x condenser were p l a c e d 108.6 gm. (0.499 moles) o f
3,5-dicarboethoxycyclopentadione-l,2,
a c i d and 20 m l . o f e t h a n o l .
sulfuric
The m i x t u r e was r e f l u x e d f o r
110 mins., w i t h a b a t h temperature
s o l u t i o n t u r n e d reddish-brown
400 m l . o f 17$
o f 117°. The r e s u l t i n g
i n color.
A f t e r c o o l i n g (under
n i t r o g e n ) , t h e s o l u t i o n was c o n t i n u o u s l y e x t r a c t e d w i t h e t h e r
f o r eleven hours.
M a i n t a i n e d under a n atmosphere o f n i t r o g e n
t h e e t h e r was removed on a w a t e r b a t h and t h e product vacuum
distilled.
Cyclopentadione, which c r y s t a l l i z e d i n the
r e c e i v i n g f l a s k , b o i l e d a t 70-80° a t 1.7-1.9 mm., and weighed
24.2 gm. (55.0$).
I t melted a t 54-55°.
L i t . 56°
A i r v e r y r a p i d l y decomposes t h i s d i k e t o n e i
(31).
However,
when s e a l e d o f f under n i t r o g e n and kept a t a p p r o x i m a t e l y 0°
i t i s s t a b l e f o r a t l e a s t s i x months.
On c o n t a c t w i t h s k i n ,
prominent b l a c k s p o t s form a f t e r some t i m e , and r e m a i n f o r a
long period.
Cvclopentane-1.2-diol (VI)
I n t o a g l a s s - l i n e r was p l a c e d a s o l u t i o n o f 12.5 § «
m
(0.128 moles) o f c y c l o p e n t a n e d i o n e - 1 , 2
i n 50 m l . o f a b s o l u t e
e t h a n o l and 0.104 gm. o f p l a t i n u m o x i d e .
The l i n e r was p l a c e d
i n a bomb whose t o t a l v o i d was 278 c c .
The a i r was t h o r o u g h l y
f l u s h e d o u t o f t h e bomb w i t h hydrogen.
The bomb was t h e n
charged t o 500 p . s . i . w i t h hydrogen, and s h a k i n g commenced a t
room t e m p e r a t u r e .
I n o n e - h a l f an hour t h e p r e s s u r e dropped
280 p . s . i . , whereupon t h e bomb was r e c h a r g e d t o 400 p . s . i .
25.
w i t h hydrogen and s h a k i n g recommenced.
drop o f 450 p . s . i . o c c u r r e d .
drop o f 400 p . s . i .
A f t e r 42 h o u r s a t o t a l
Complete h y d r o g e n a t i o n
required a
The c a t a l y s t was f i l t e r e d o f f , and t h e
e t h a n o l removed under r e d u c e d p r e s s u r e a t t h e w a t e r pump.
c l e a r , c o l o r l e s s , v i s c o u s l i q u i d was o b t a i n e d .
approximately
t o 20°
A
On c o o l i n g t o
-10° some c r y s t a l l i z a t i o n o c c u r r e d , b u t on warming
complete s o l u t i o n r e s u l t e d .
The
d i - p - n i t r o b e n z o a t e . p r e p a r e d i n t h e r u s u a l manner,
•was r e c r y s t a l l i z e d f r o m e t h a n o l , m.p. 90-104°. R e c r y s t a l l i z e d
once more, m.p. 9 3 - 1 2 5 ° .
L i t . , c i s - 117°; t r a n s - 145° (44)
F o r i n f r a r e d a n a l y s i s some of t h i s h y d r o g e n a t e d
p r o d u c t was vacuum d i s t i l l e d t w i c e , and made I n t o a 3.0% s o l u t i o n
i n pure c h l o r o f o r m . ( F i g . 1, p. 37)
Cyclopentadiene
The
dehydrating
(VII)
column c o n s i s t e d o f a P y r e x
tube,
30 cm. l o n g and 22 mm. i J d . , wound e x t e r n a l l y i n a s p i r a l w i t h
approximately
900 cm. o f No. 27 Chromel-"A" w i r e . , A thermo-
c o u p l e w e l l was c o n s t r u c t e d so t h a t i t would r e s t i n t h e c e n t r e
o f t h e c a t a l y s t mass.
provided
To one end o f t h e t u b e , a n i n l e t was
so t h a t t h e s u b s t a n c e t o be d e h y d r a t e d and n i t r o g e n gas
c o u l d be i n t r o d u c e d s i m u l t a n e o u s l y .
To t h e " e x i t - e n d " o f t h e
t u b e , a n a r r o w e r p i e c e o f g l a s s t u b i n g was a f f i x e d , w h i c h i n
t u r n c o u l d be connected t o two c o n s e c u t i v e
"Dry-ice"-acetone
cooled t r a p s .
T h i s tube was f i l l e d w i t h p e l l e t s o f commercial 8-mesh
alumina.
was
W i t h a slow stream o f n i t r o g e n f l u s h i n g t h r o u g h , i t
h e a t e d a t 4000 f o r a p p r o x i m a t e l y
48 h o u r s t o d r y and
26.
a c t i v a t e the c a t a l y s t .
W i t h the temperature a t 400 i 3°, t h e
e x i t end connected t o t h e two D r y - i c e " - a c e t o n e t r a p s , and a
u
slow stream o f n i t r o g e n f l u s h i n g t h r o u g h t h e t u b e , 2.47
t r a n s - c y e l o p e n t a n e - l , 2 - d i o l was
column over a p e r i o d o f 10-15
gm.
of
slowly introduced i n t o the
minutes.
The p r o d u c t , w h i c h
possessed t h e v e r y c h a r a c t e r i s t i c odor o f c y c l o p e n t a d i e n e ,
c o n s i s t e d o f 0.4
m l . (21$)
of a s l i g h t l y g r e e n i s h o i l f l o a t i n g
on a p p r o x i m a t e l y one m l . o f w a t e r .
The m a l e i c a n h y d r i d e adduct o f t h i s p r o d u c t , t w i c e
r e c r y s t a l l i z e d from e t h e r had a m.p.
of
161.5-162.5°. L i t . 165°
(32).
Potassium Cyclopentadienide ( V I I I )
C y c l o p e n t a d i e n e was generated' by s l o w l y r e f l u x i n g
d i c y c l o p e n t a d i e n e and c o l l e c t i n g t h e d i s t i l l a t e a t 44-46° ( 4 3 ) .
T h i s m a t e r i a l was s t o r e d a t " D r y - i c e " temperature t o keep p o l y m e r i z a t i o n a t a minimum.
J u s t b e f o r e use t h e c y c l o p e n t a d i e n e
was r e d i s t i l l e d - b.p. 41-42°.
The p o t a s s i u m used i n t h i s r e a c t i o n was h a n d l e d i n t h e
f o l l o w i n g manner:
I n s i d e a box f r o m w h i c h a l l a i r was
displaced
w i t h d r y n i t r o g e n gas, the p o t a s s i u m was p l a c e d i n t o a deep
mortar c o n t a i n i n g pure anhydrous benzene.
The o u t e r o x i d e -
.coating was c u t o f f , and t h e f r e s h l y cut m e t a l t r a n s f e r r e d i n t o
a t a r e d , beaker c o n t a i n i n g anhydrous benzene.
p o t a s s i u m (10.7
gm.)
was t h e n i n t r o d u c e d i n t o a 500
bottomed f l a s k c o n t a i n i n g a p p r o x i m a t e l y 100
anhydrous benzene.
The
required
ml. round-
ml. of pure,
The f l a s k was t h e n s t o p p e r e d .
The
potassium
s c r a p s r e m a i n i n g i n the mortar were i m m e d i a t e l y decomposed by
27.
the c a u t i o u s a d d i t i o n of d r y t e r t - b u t y l a l c o h o l .
Small
specks
o f p o t a s s i u m r e m a i n i n g on t h e k n i f e and tweezers were a l s o
decomposed w i t h t e r t - b u t y l a l c o h o l .
The f l a s k c o n t a i n i n g 11.0 gms. (0.282 moles) o f
p o t a s s i u m was u n s t o p p e r e d ,
and heated u n t i l t h e m e t a l
liquified.
Once a g a i n t h e f l a s k was s t o p p e r e d , wrapped i n a t o w e l and
s h a r p l y shaken t h r e e t i m e s .
An e f f i c i e n t r e f l u x - c o n d e n s e r
was t h e n a t t a c h e d t o t h e f l a s k i n p l a c e o f t h e s t o p p e r , and
w i t h d r y n i t r o g e n s l o w l y sweeping i n t o t h e f l a s k , t h e c o n t e n t s
were a l l o w e d t o come t o room t e m p e r a t u r e .
Then, w i t h o u t
intro-
d u c i n g a i r , a s o l u t i o n o f 23.0 gm. (0.348 moles) o f c y c l o p e n t a d i e n e i n 100 m l . o f p u r e , anhydrous e t h e r was s l o w l y added
t o t h i s f i n e g r a n u l a r p o t a s s i u m i n benzene.
A f t e r the i n i t i a l
r e a c t i o n had s u b s i d e d , t h e m i x t u r e was r e f l u x e d f o r f o u r h o u r s .
The e t h e r and benzene were removed under reduced p r e s s u r e and
the s l i g h t l y p i n k i s h s a l t f i n a l l y d r i e d a t 0.1 mm. a t 60° f o r
three hours.
T h i s d r y s a l t , kept i n a w e l l - s t o p p e r e d f l a s k , was
i
s t a b l e f o r a t l e a s t t h r e e months.
Cyclopentadiene
( I X ) from P o t a s s i u m
Cyclopentadienide
I n t o a 100 m l . round-bottomed f l a s k was p l a c e d 4.37 gm.
o f p o t a s s i u m c y c l o p e n t a d i e n i d e , and t h e n c o o l e d t o -80°.
To
t h i s c o l d s a l t , a p p r o x i m a t e l y 30 m l . o f c o l d (-80°) c o n c e n t r a t e d
h y d r o c h l o r i c a c i d was added, t h e c o n t e n t s i n t h e r e a c t i o n f l a s k
being w e l l s t i r r e d .
Twenty m l . o f i c e - c o l d w a t e r was. n e x t
i n t r o d u c e d , and t h e m i x t u r e d i s t i l l e d a t a b a t h temperature o f
60°.
The r e c e i v e r c o l l e c t i n g t h e product was c o o l e d i n " D r y - i c e "
acetone m i x t u r e .
(43.3$).
Approx. 1.2 gm o f c y c l o p e n t a d i e n e was o b t a i n e d .
28.
A slow a d d i t i o n o f 20 m l . o f r e d i s t i l l e d b u t a n o l a t
j u s t above i t s f r e e z i n g p o i n t t o 24 gm.
of potassium
cyclo-
p e n t a d i e n i d e , f o l l o w e d by a d i s t i l l a t i o n , u s i n g a r e f l u x
condenser w i t h a j a c k e t temperature
3*9
gm.
(26$)
of
o f 50° as a column y i e l d e d
cyclopentadiene.
D i e t h y l e s t e r o f 2 . 3 - d i h y d r a z o b i c y c l o (2.2.1.)-5-heotene-2.
3 - d i c a r b o x y l i c a c i d (X) (18)
N.N-Dicarbethoxv-endomethylenetetra
hydropvridazine
I n a 250-ml. round-bottomed f l a s k equipped w i t h an
e f f i c i e n t r e f l u x condenser were p l a c e d 3-9
pentadiene
gm.
of the c y c l o -
o b t a i n e d i n the l a s t r e a c t i o n and 11.0
gm.
cyclopentadiene obtained from d i c y c l o p e n t a d i e n e .
r e f l u x condenser 33.27 gm.
s l o w l y added.
m i x t u r e warmed up on t h i s a d d i t i o n .
After refluxing for
p r e s s u r e , and t h e
v e r y v i s c o u s , s l i g h t l y y e l l o w i s h l i q u i d was
y i e l d i n g 43.9
0.2-0.25 mm.:
a t 0.5 mm.;
gm.
(96$)
colorless,
of e t h y l a z o d i c a r b o x y l a t e .
removed under reduced
ml.
The r e a c t i o n
12 h o u r s , the r e s u l t i n g m i x t u r e was
i n d i c a t i n g the d i s a p p e a r a n c e
e t h e r was
Through the
o f e t h y l a z o d i c a r b o x y l a t e i n 80
o f pure anhydrous e t h e r was
approximately
of
The
remaining
vacuum d i s t i l l e d ,
of p r o d u c t b o i l i n g a t 109-112° a t
Dibromo d e r i v . , m.p.
dibromo d e r v . , m.p..
66.0-66*5° L i t . b.p.
67°
(18)
( D i - e t h y l e s t e r of 2 . V D i a z a b i c y c l o ( 2 . 2 . 1 )
a i c a r b o x y l i c a c i d ) (XIO
120°
heptane-2.^-
(18)
I n t o a g l a s s - l i n e r were p l a c e d 11.55
o f d i e t h y l e s t e r o f 2,3-dihydrazobicyclo(22.2.1)
gm.
(0.0481 moles)
5-heptane-2,
3 - d i c a r b o x y l i c a c i d i n 38 m l . o f a b s o l u t e methanol and
O.O87
gm.
29.
of platinum oxide.
The l i n e r was a t t a c h e d t o t h e h y d r o g e n a t o r
w i t h a t o t a l v o i d of 4260 c c , and t h e a i r c o m p l e t e l y f l u s h e d
out w i t h hydrogen.
t o 239
The l i n e r was t h e n charged w i t h
p . s . i . , and s h a k i n g commenced.
hydrogen
The r e q u i r e d t h e o r e t i c a l
drop of 4.1 p . s . i . o c c u r r e d i n two h o u r s , whereupon hydrogena t i o n was s t o p p e d , t h e l i n e r removed f r o m t h e h y d r o g e n a t o r and
t h e c a t a l y s t removed by f i l t r a t i o n .
The p r o d u c t I n t h i s
methanol s o l u t i o n was used" d i r e c t l y i n the n e x t r e a c t i o n .
I n a p r e l i m i n a r y r u n , 9-29
2,3-dihydrazo(2.2.1)
gm.
of diethyl e s t e r of
5-neptene-2,3-dicarboxylic a c i d
hydrogenated a t 22.00 p . s . i .
A f t e r one hour 97$ o f t h e
t h e o r e t i c a l amount o f hydrogen was a b s o r b e d j
h y d r o g e n a t i o n was complete.
was
i n two hours
F u r t h e r h y d r o g e n a t i o n f o r an hour
r e s u l t e d i n no f u r t h e r d r o p I n p r e s s u r e .
The p r o d u c t
was
i s o l a t e d by f i l t e r i n g o f f t h e c a t a l y s t , removing the methanol
a t t h e w a t e r - a s p i r a t o r , and vacuum d i s t i l l i n g t h e r e s i d u e .
The f r a c t i o n b o i l i n g a t 115-117° a t 0.9-1.0 mm.
and weighed 7.80
gm.
was
collected
(84.3$)
2 3 - D i a z a b l c y c l o ( 2 . 2 . 1 ) heptane
T
(Cuprous C h l o r i d e Complex)
( X I I ) (18)
To t h e m e t h a n o l i c s o l u t i o n o f the d i e t h y l e s t e r o f
2,3-diazabicyclo(2.2.1)heptane-2,3-dicarboxylic acid obtained
i n t h e l a s t r e a c t i o n , 16.0
added.
gm.
o f p o t a s s i u m h y d r o x i d e was
The r e s u l t i n g s l i g h t l y y e l l o w i s h s o l u t i o n was
r e f l u x e d on a w a t e r - b a t h f o r two h o u r s .
gently
The p o t a s s i u m c a r -
bonate, w h i c h formed I n the r e a c t i o n , was f i l t e r e d o f f , and
30.
washed twice w i t h 10 ml. o f a b s o l u t e methanol.
The potassium
carbonate, a f t e r d r y i n g , weighed 13.24 gm. (99.8$).
The com-
bined methanolic f i l t r a t e and washings was c a r e f u l l y
evaporated
o f f under reduced pressure and the r e s i d u e was steam d i s t i l l e d .
Steam d i s t i l l a t i o n was continued u n t i l no r e d c o l o r was
produced when c u p r i c c h l o r i d e was added t o a few drops o f the
distillate.
To the steam d i s t i l l a t e , 8.2 gm. (0.0481 moles)
of c u p r i c c h l o r i d e d i h y d r a t e was slowly added w i t h
The r e d cuprous
c h l o r i d e complexrimmediately
c i p i t a t e as long g l i s t e n i n g prisms.
p r e c i p i t a t e was f i l t e r e d
stirring.
started to pre-
The next day t h i s r e d
o f f , washed w i t h 30 ml. o f water, and
d r i e d a t 0.1 mm. f o r two hours oyer phosphorous pentoxide.
T h i s d r i e d product weighed 3*42 gm.
crop was c o l l e c t e d .
(35$).
The t o t a l weight
(44.6$) (From d i e t h y l e s t e r o f
I n a week, a second
o f product was 4.37 gm.
2,3-dihydrazobicyclo$2.2.1)-5-
heptene-2,3-dicarboxylic acid)
Anal.
C a l c d . f o r CjHS^.CuCl.^B^O
"
Found:
"
C5H8N.CUCI.
8
C l , 17.37
:
C l , 18.17
C l , 18.01, 18.10
Cis-cyclopentane-1.^-diamine
(Stannous
C h l o r i d e Complex) ( X I I I ) ( 1 8 )
A mixture o f 2.707 gm. o f the cuprous c h l o r i d e comp l e x of 2 , 3 - d i a z a b i c y c l o ( 2 . 2 . 1 ) heptane, 24.5 gm. of mossy t i n
and 40 ml. o f concentrated h y d r o c h l o r i c a c i d was heated i n a
b o i l i n g water bath f o r 6.5 hours.
Then t o the s t i l l hot r e a c t i o n
mixture, 10 ml. o f c o n c e n t r a t e d h y d r o c h l o r i c a c i d was added.
31.
A f t e r c o o l i n g t o 6 0 ° , the r e s u l t i n g mixture was f i l t e r e d
through a $i,:nt.er-e.d:-«jlass Ct f u n n e l .
A f t e r standing a t 5°
over
n i g h t , the long s i l k y needles were f i l t e r e d o f f . Drying over
phosphorous pentoxide and sodium hydroxide p e l l e t s a t 1.0 mm.
f o r s i x hours i n a vacuum d e s i c c a t o r gave 5*563 gm. (74-.3$)
of a product melting a t 1 5 5 - 1 6 3 ° , L i t . 145-146° ( 4 6 ) ; 172° (18).
Anal.
Calcd.
»
Found:
f o r C^HgCNR^.(SnCl )2.2HCl.H 0
2
"
2
C5H8(NH )2(SnCl )2.2HCl
2
2
: N,
: H, 4.91$
5.07$
N (Duma) 4.90, 4.97$
S u c c i n i c A c i d (XIV) (46)
To 5.06 gm. of the stannous c h l o r i d e complex of
cis-cyclopentane-l,3-diamine d i h y d r o c h l o r i d e , a s o l u t i o n o f
12.24 gm. of potassium permanganate i n 122.5 ml. of water was
added.
The mixture was r e f l u x e d i n a b o i l i n g water bath f o r
15 minutes and immediately cooled.
The manganese d i o x i d e was
f i l t e r e d o f f and washed w i t h water.
The combined f i l t r a t e s ,
i f colored, were d e c o l o r i z e d w i t h s u l f u r d i o x i d e and continuously
extracted w i t h pure ether f o r 60 hours.
The ether from t h i s
e x t r a c t was evaporated, l e a v i n g a mixture of white and. s l i g h t l y
yellowish crystals.
R e c r y s t a l l i z a t i o n from water (charcoal)
y i e l d e d 0.109 gm. (9.7$) of product w i t h a m.p. Of 176-J#d°.
A s m a l l p o r t i o n , r e c r y s t a l l i z e d twice more, had a m.p. of
179-1800.
The reported m.p. of s u c c i n i c a c i d i s 188° but the
above o n c e - r e c r y s t a l l i z e d product d i d not depress the mixed
m.p. w i t h a u t h e n t i c s u c c i n i c a c i d .
32.
M.p.
of once r e c r y s t a l l i z e d commercial s u c c i n i c a c i d : 1 8 4 - 1 8 5 . 5 °
: 184.5-186°
mixed m.p.
Di-p-biomophenacyl e s t e r , m.p.
L i t . m.p.
211°
208.5 -
210°
(36)
D i m e t h y l S u c c i n a t e ( X V ) ( 7 ) ( C h a r a c t e r i z e d as the H y d r a z i d e )
To a s o l u t i o n o f 1 5 mgm.
i m a t e l y 4 . 5 m l . of methanol a t 0 ° ,
of s u c c i n i c a c i d i n approxa s l i g h t excess of d i a z o -
methane i n c o l d e t h e r was s l o w l y added w i t h s w i r l i n g .
After
a p p r o x i m a t e l y 15 minutes t h e r e s u l t i n g s o l u t i o n was a l l o w e d t o
come t o room temperature and t h e e t h e r , diazomethane,
and
methanol removed i n a stream o f n i t r o g e n .
To t h e e s t e r o b t a i n e d i n t h e same t e s t - t u b e , used
i n t h e above p r e p a r a t i o n
0.14 m l . o f 85$ h y d r a z i n e h y d r a t e
was added t o g e t h e r w i t h 5 d r o p s o f m e t h a n o l .
The c o n t e n t s o f
t h e tube were c o o l e d i n a " D r y - i c e " Q a c e t o n e m i x t u r e , t h e tube
e v a c u a t e d , s e a l e d and t h e n h e a t e d a t 1 2 0 ° f o r one h o u r .
A f t e r c o o l i n g , the tube was opened and t h e c r y s t a l l i n e p r o d u c t
s c r a p e d out and p r e s s e d on f i l t e r paper t o d r y .
Recrystalli-
z a t i o n f r o m e t h a n o l gave w h i t e c r y s t a l s w h i c h m e l t e d a t 164165°.
L i t . 167°
(14).
The above c r y s t a l s , when mixed w i t h
s u c c i n y l h y d r a z i d e o b t a i n e d from a u t h e n t i c a l d i e t h y l
gave a m.p.
succinate,
of 1 6 3 . 5 - 1 6 4 . 5 .
0
S u c c l n v l H y d r a z i d e (XVI) (9.14)
I n t o a 20 m l . C^iius tube c o n t a i n i n g 1 . 0 0
gm.
(0.00|69
moles) of e t h y l s u c c i n a t e a t 0 ° , 0 . 5 9 m l . ( 0 . 0 1 0 3 moles) o f
h y d r a z i n e h y d r a t e a t Oo was added.
The c o n t e n t s o f t h e t u b e
33.
were f r o z e n out i n a Dry-ice"-acetone mixture, the
!,
s e a l e d , and then heated at 1 2 0 °
evacuated,
tube
f o r one hour.
The c r y s t a l l i n e product r e c r y s t a l l i z e d from e t h a n o l weighed
0.77 gm. (91.6$), had a m.p.
of 1 6 4 . 5 - 1 6 5 . 5 ° .
L i t . l67°(l£).
E t h y l e n e D i u r e t h a n (XVII) ( H )
To 0.592 gm.
o f s u c c i n y l hydrazide i n a 100 ml.
beaker, 6.0 ml. of l N K t i ^ d r o c h l o r i c a c i d and 4 ml. of water
were added.
was
A f t e r the h y d r a z i d e d i s s o l v e d , 10 ml. o f ether
added and the mixture c o o l e d t o - 5 ° i n an i c e - s a l t
To t h i s c o l d mixture, 0.689 gm. o f sodium n i t r i t e was
added w i t h s t i r r i n g .
was
The temperature
not allowed t o r i s e above 2 ° .
hath.
slowly
of the r e a c t i o n mixture
A f t e r the a d d i t i o n was
completed, the mixture was w e l l s t i r r e d and the e t h e r l a y e r
separated.
The aqueous l a y e r was
e x t r a c t e d once w i t h 10 ml.
of f r e s h ether and the combined ether e x t r a c t s were shaken
once w i t h sodium b i c a r b o n a t e , s o l u t i o n , f i l t e r e d , and
washed once w i t h 15 ml. of water.
then
The e t h e r l a y e r was
separated,
d r i e d w i t h c a l c i u m c h l o r i d e f o r f i v e minutes and f i n a l l y w i t h
anhydrous c a l c i u m s u l f a t e .
To t h i s d r i e d e t h e r s o l u t i o n o f
s u c c i n y l a z i d e p l a c e d i n an Erl§nmeyer
a b s o l u t e e t h a n o l was
a hot p l a t e .
f l a s k , 20 ml. o f
added, and the s o l u t i o n b o i l e d g e n t l y on
When the t o t a l volume was
reduced t o a p p r o x i -
mately 1 ml. the Erlgnmeyer was
t r a n s f e r r e d t o a steam bath
where e v a p o r a t i o n was
t o dryness.
proceeded
c r y s t a l l i n e product weighed 0.145
of 1 0 6 . 5 - 1 0 8 ° .
L i t . 110°
(13)
gm.
T h i s white
(17.5$) and had a m.p.
34-.
H y d r o l y s i s of E t h y l e n e d i u r e t h a n ( X V I I I ) (7)
I n a 30 m l . two-necked
d i u r e t h a n e i n 6.0
f l a s k , 130 mg.
of e t h y l e n e -
m l . o f 4 8 $ hydrobromic a c i d was
refluxed
for
two h o u r s w i t h a s l o w stream of C 0 2 - f r e e n i t r o g e n
the
system.
sweeping
T h i s n i t r o g e n swept the c a r b o n d i o x i d e g e n e r a t e d
i n the r e a c t i o n out t h r o u g h t h e condenser i n t o a gas d i s p e r s i o n
tube immersed i n l N - c a r b o n a t e f r e e sodium h y d r o x i d e s o l u t i o n .
A d d i t i o n o f 100 m l . of IN ammonium c h l o r i d e s o l u t i o n and
gm.
o f barium c h l o r i d e i n 2 0 m l . o f w a t e r t o t h e
h y d r o x i d e p r e c i p i t a t e d t h e BaCO^.
0.28
sodium
This carbonate, a f t e r being
f i l t e r e d t h r o u g h a g l a s s - s i n t e r e d c r u c i b l e ( M - p o r o s i t y ) , washed
w i t h b o i l i n g wateraand a b s o l u t e a l c o h o l and t h e n d r i e d f o r one
hour a t 1 2 0 ° weighed
239 mgm.
(94.8$).
The c o n t e n t s o f t h e r e a c t i o n f l a s k were e v a p o r a t e d
j u s t t o d r y n e s s a t room t e m p e r a t u r e under r e d u c e d p r e s s u r e .
E x c e s s m e t h a n o l i c KOH was added, and the s o l u t i o n a g a i n d i s t i l l e d to dryness, the d i s t i l l a t e
collected i n a receiver
cooled i n a "Dry-ice"-acetone mixture.
Hydrogen c h l o r i d e
bubbled i n t o the d i s t i l l a t e , and t h e r e s u l t i n g
precipitate
was f i l t e r e d o f f . R e c r y s t a l l i z e d f r o m w a t e r - m e t h a n o l ,
the
e t h y l e n e diamine d i h y d r o c h l o r i d e , a f t e r d r y i n g o v e r P2O5
KOH
p e l l e t s , weighed 70.9
mgm.
(85$).
P i c r a t e , r e c r y s t a l l i z e d from a b s o l u t e e t h a n o l ,
melted w i t h
dec.
a t 229.5-232°.
was
L i t . 230 - 235°
(33)
a n
d
35.
Cyclopentanone
Two hundred gm.
(57)
o f powdered a d i p i c a c i d and 10.0
gm.
of powdered Ba(0H)2 were t h o r o u g h l y mixed and t h e n h e a t e d a t
300° i n a s a l t - h a t h .
The crude c y c l o p e n t a n o n e and w a t e r
d i s t i l l e d o v e r a t 101-102°.
The d i s t i l l a t e was
saturated
w i t h anhydrous
K2CO3.
w i t h anhydrous
C a C l 2 , and d i s t i l l e d t h r o u g h a s h o r t column t o
y i e l d 886 gm.
at atmospheric
The c y c l o p e n t a n o n e was
separated, d r i e d
(77.1$) o f a c y c l o p e n t a n o n e b o i l i n g a t 128-129°
pressure.
Cyclopentanol
Cyclopentanone
(SXI) (47)
(88 gm.,
105 moles) was
s l o w l y added,
o v e r a p e r i o d of 105 m i n u t e s , t o a w e l l s t i r r e d s u s p e n s i o n o f
12.3 gm.
(0.324 moles) o f l i t h i u m aluminum h y d r i d e I n approx.
300 m l . o f p u r e , anhydrous
ether.
The r e a c t i o n m i x t u r e was
t h e n r e f l u x e d f o r one and a h a l f h o u r s .
was
C a u t i o u s l y , wet
ether
t h e n i n t r o d u c e d , f o l l o w e d by c o l d 10$ H 2 S O 4 , u n t i l most
o f the i n o r g a n i c s o l i d s d i s s o l v e d and two d i s t i n c t
formed.
T h i s m i x t u r e was
phases
then continuously extracted w i t h
e t h e r f o r 20 h o u r s , and the r e s u l t i n g e t h e r e x t r a c t d i s t i l l e d .
The f r a c t i o n b o i l i n g a t 124-128© was
collected.
t i l l a t e d r i e d w i t h CaS04 and r e d i s t i l l e d
This
y i e l d e d 38.8
(43.5$) o f c y c l o p e n t a n o l b o i l i n g a t 138-139.5°.
disgm.
C y c l o p e n t e n e ( X X I I ) (16)
I n a 250 m l . two-necked f l a s k , equipped w i t h a
s e p a r a t o r y f u n n e l and a 20 cm. l o n g , f o u r - n e c k e d
f i l l e d w i t h p i e c e s o f g l a s s t u b i n g ( 5 mm.
Wurtz column
l o n g and 6 mm. i n
d i a m e t e r ) , was p l a c e d 1 5 . 0 gm. o f 85$ p h o s p h o r i c
acid.
The
column was a t t a c h e d t o a condenser, and t h e r e c e i v i n g f l a s k
was heated t o 1 7 3 ° , u s i n g a s a l t - b a t h o f p o t a s s i u m
and p o t a s s i u m
nitrate.
From t h e d r o p p i n g
nitrite
f u n n e l , over a
p e r i o d o f two h o u r s , 4 3 . 0 gm. o f c y c l o p e n t a n o l was s l o w l y
added.
to
A f t e r t h i s a d d i t i o n , t h e b a t h t e m p e r a t u r e was r a i s e d
200° and m a i n t a i n e d a t 200° f o r 40 m i n u t e s .
The
temperature o f t h e d i s t i l l a t e d i d n o t r i s e above 8 5 ° d u r i n g
the whole o p e r a t i o n .
The d i s t i l l a t e was d r i e d w i t h anhydrous
c a l c i u m c h l o r i d e , t h e n w i t h anhydrous c a l c i u m s u l f a t e .
The .
d r i e d d i s t i l l a t e was d i s t i l l e d t h r o u g h a 25 em. l o n g - 1 cm.
i.d.
eolumn, packed w i t h 4 mm. g l a s s h e l i c e s , y i e l d i n g
3 2 . 0 gm.
(95:*9$)
of product
boiling
at 42-44°.
Trans-cyclopentane-1.2-diol
L i t . 46©.
( X X I I I ) (44)
I n a 3-necked, 1 - l i t r e f l a s k , equipped w i t h a
condenser, d r o p p i n g f u n n e l and s t i r r e r , was p l a c e d 3 1 * 5 gm.
( 0 . 4 6 4 moles) o f c y c l o p e n t e n e .
of the r e a c t i o n mixture
C o n t r o l l i n g the temperature
so t h a t o n l y s l i g h t r e f l u x i n g was
o b t a i n e d , a m i x t u r e o f 207 gm. o f 30$ hydrogen p e r o x i d e
(0..?41/}moles) and 558 gm. o f 90$ f o r m i c a c i d (PQ:°w moles)
was s l o w l y added w i t h s t i r r i n g
through the dropping
funnel.
3 7 .
A f t e r t h i s a d d i t i o n was complete, t h e r e a c t i o n m i x t u r e was
kept a t 40° f o r f o u r h o u r s .
The n e x t day, t h e f o r m i c a c i d
and water were removed under reduced p r e s s u r e (water a s p i r a t o r ) .
The r e m a i n i n g o i l was d i s s o l v e d i n a p p r o x i m a t e l y 1 0 0 m l . o f
1 2 $ sodium h y d r o x i d e , and t h e n r e f l u x e d f o r 40 m i n u t e s .
To
t h e c o n t e n t s o f t h e r e a c t i o n f l a s k , d i l u t e s u l f u r i c a c i d was
added u n t i l t h e m i x t u r e was j u s t s l i g h t l y b a s i c ( p H . 8 ) .
The
water was d i s t i l l e d o f f under reduced p r e s s u r e and t h e
r e m a i n i n g o i l was vacuum d i s t i l l e d .
a b.p. o f
1 1 0 - 1 1 3 °
at
mm.,
2 - 3
The p r o d u c t , w h i c h had
weighed 2 6 . 4 gm.
( 5 5 - 9 $ ) .
D i - p - n i t r o b e n z o a t e , c r y s t a l l i z e d from e t h a n o l ,
141.5-142.5°.
m.p.
L i t . 143°
(44).
y
, f
#
"i.0
"
5.0
1.C
u
?.o
19.0
TO
lit
l*i
/
\
I
\
w
'
\h
!
U'
\F il
J—[°*
TR
fi«s <
(xxvi)
y\Jj
\
/
1
HYDRttENATED
s 1 6
° (l)
v
i
\j
.*«
ieoo
c
m
- i
looo
Pig.
2DOC
IIH
'
tut
*«o
-
itno
im
an
1 . — I n f r a r e d spectrum o f ( c i s - t r a n s ) c y c l o p e n t a n e -
1 , 2 - d i o l , ( V I I ) , and t r a n s - c y c l o p e n t a n e - l , 2 - d i o l ( X X V l ) , as
Z% s o l u t i o n s i n c h l o r o f o r m .
Pol,
The a n a l y s i s was done b y E. H.
o f t h e B r i t i s h Golumbia R e s e a r c h
Council.
38
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