Huygens Institute - Royal Netherlands Academy of Arts and Sciences (KNAW)
Citation:
Romburgh, G. van, Nitro-derivatives of alkylbenzidines, in:
KNAW, Proceedings, 18 I, 1915, Amsterdam, 1915, pp. 757-760
This PDF was made on 24 September 2010, from the 'Digital Library' of the Dutch History of Science Web Center (www.dwc.knaw.nl)
> 'Digital Library > Proceedings of the Royal Netherlands Academy of Arts and Sciences (KNAW), http://www.digitallibrary.nl'
-1-
757
Chemistry.
"Nit1'O-cle1'ivatives of alkylbeuzidines". By G.
RO:MBUIWH. (Oommunicated by Prof. P.
VAN
VAN
ROMBURGn).
(Communicated in the meeting of October 30, 1915).
MERT1'lNS 1) bas obtained in 1877 as a byproduct in the nitration
of dimethylamlme an ol'ange-yellow compound soluble with difficulty
in alcohol, which he named Isodinitl'odimet!Jylaniline. From this was
obtained on boiling wirh concent1'ated mtric arid 11 product which
he again inve5tigitted a few years later 2) and took It fol' dinitrophellylmeth.) 1111t1'amine. Fl'om tIllS was formed on bolling with
phenol a splendld red coloured compound wInch was described as
tetramtrodimethylazobenzelJe. Shortly afterwal'ds P. VAN ROl\lBURGH .1)
showed that these compounds found by Ml!lHTmNS are derivatIves of a
tetramLrobenzieline without, however, eletermining the pQsihon of the
nitl'o-groups.
1 resolved to endeavoUl' to elucidate the stl'llcture of these products,
anel at the same time to stuely also a munber of nitro compounels in
the a1kylbenzidll1e series in adchtion to some rednction proelurts tbereof.
The tetl'anitrotetl'ameth) lbenzidine, which in the circul11stances, is
formed only 111 small quantlty, in the above 11itration is obtained
in a yield of about 35°/0 of the dimetby1alliline employed, when
we opel'ate as follows:
30 grams of dimetbylanihne are dissolved in 900 c.c. ofnitl'ic acid
D. 1.11, whicb are cooled in iee-water to abont 5°. Aftel' thorough
shaking and leaving it 1'01' some time in the ice-water it is left at
the orelinal'y tempe1'ature. The pL'oduct that bas formed o\'er nigbt
is collected, boiled with alcohol anel filtered thl'ough a hot waterfunne1. The slllJstance so obtained is already very pure and, when
recrysütllised from phenol, it decompo'3es at 272°.
Aqueolls potassillm hydroxide is supposed not 10 act on th is
compound. I could, bowever, ascel'tain that on prolonged boiling
some fOl'mation of dimethylamine takes pI ace.
The mannel' in which the product is formed justifies the belief that
the nitro-gL'OllpS occupy tbe pOSitiOIlS 3.3'.5.5'. For in the nitration
of dimethylamline, as Rhown by PINNOW 4) there is formed, at least
in eliluted 5ulphlll'ic acid solution, some orthonitroclimethylaniline,
wbich product is not readily nitl'ated any further. As nitric acid of
1) Diss. Leiden. 1877.
2) Bel'. d D. Che'!n. Ges. 19, 2123 (1886).
S) Rec. d. Trav. Chim. 5, 240 (1886).
4) Bel'. d. D. Chem. Ges. 32 f 1666 (1899)
-2-
758
low roncentration; sueh as used in the above experiment, may aet
as an oxidiser, it is llkely to altack this o-nitrodimethylani!ine in
the stlll nnoccupied pal'a-positions and ~ause the formation of
0.0' -dinitrotetramethy lbenzidine, whieh is more readlly rapable of
fUl'ther nitl'ution, partirularly in the presenee of nitl'ous arid. As is
well-known, the nitro-group, in this prolonged nitration, exerts an
influence of such a kind that the new!y entel'ed nitro-gl'oupS arrange
themselves meta in regal'd to the previous ones.
rt mayalso be possible that the dImethylamine itself i5 oxidised
direetly to a benzidine derivative of wbich it may be assurned (in
analogy with different other benzene derivatives in whICh the ]Jamposition in regard to the aminogroup has been occupied) that the
nitration wiII take place in a cOrt'espondmg manner. Hence, I have
trled in the first place to prepare the 0.3'.5.5' tetranitrotetrarnethy 1benzidine synthetlcally.
Aftel' seyeral vain efforts, to which 1 will not now refer, I have
taken the following rourse.
/
I started from p.-diphelloldiethylether, wbich I pI'epal'ed aecording
to HIRSCH'S directions I) and then tt'eated with furmng nitric acid.
The dark eoloured sollltion, on heating soon beeame paie yellow
and on cooling the tetraniirodiphenoldiethylethPl' crystaJlises in long,
transparent colourless needles mt'lting at 2560 -257 0 •
Analysis: fouud
45,6 oio C. 3.5°/oH 13.5°/oN.
calculated for CISH14N4010 45.5"
3.3"
13.3"
Of the tetranitrodiphenolethel', I placed 2 grams iu a tube of
resistance glass and added a solution of 1 gram of dimethy lamine
in 2.5 cc. of alcohol. The sealed tu be was first plaeed in a boiling
water-bath, whieh caused the rontents to slovl'ly turn au orange-red.
I further also heated for some hOUl'S at 1200 when it appeared that
a red crystalline mass had deposited. This product was collected
and washed with warm alcohol and warm y"ater, when it appeared
tha,t, the compound dissolved in the lattel'. On addition of strong
pydrochloric acid to the red colollred solutioJl, a yellow coloured compound was precipitated which could be recrystallised from aeetic
acid, and melted at 223 It struck me as not being irnprobable
that this product WttS tetranitrodiphenol and indeed it caused no
lowering of the melti.ng poi.nt when mixed with this substance.
As to its structure, the opinions remained, however, divided. By
boiling it with stl'ong nitrie acid I sllcceeded, as did SCRJl.nDT aud
SCRULTZ 2), in converting it into picric acid, so that the posItion of the
0
,
1) Ber d. D. Chem Ges. 22, 335 (1889).
g) Ann. d. Chemie 207, 334 (1881).
-3-
759
nitro-gl'oupS in this tetranitrodiphenol, and therefore also in the
ether obtained by me, must bf' 3.3'.5.5'.
No tetranitrotetramethy lbenzidine hael formeel mean winie. Hence,
I made anothel' experiment where I allowed monomethylamine to
act on the tetranltl'odiphenoldiethylethel'. The contents of Ihe tllbe
also turned orange-red when immersed in the boihng water-bath
and aftel' tlle operation a red crystaIline mass had again deposlted
in rhe tube.
Again I washed with warm alcohol and warm wate'r, but the
'1atter soon ran through colomless whilst a dark reel cl'ystallme muss
was lefr behind on the filter. It conld be recl'ystalliseel from phenol.
The compound so obtained decomposed at 282°,
Hence, the synthesis of tetranitl'oelimethylbenzidme had beell successful and now it was also proved beyond doubt that it was a 3.3',5.5'
compound, which, of COlll'Se. also appJies to the (et]'anitl'otetramethyl~
benzidine anà its derivati ves.
The difficult decomposition by boi1ing aqueous potassium hydroxide
must be most likely attributed to the slight solubility of this
compound.
The above eited experiments now also paved the way fol' the
synthesis of all kinds of tetranitroalkylbenzidines.
For instance, I allo wed ethylamine to act on (he tetI'anitrodiphenolether and obtained a compound which, when recrystallised fl'om
ethyl benzoate, crysta1lises in yellowish~red smull needies, wl1lch
melt at 248 0 with decomposition. This same substance, I also could
prepal'e fi'om tetraethy Ibenzidine.
I haye also allowed propyl~, isopl'opy 1- isobutJ I~ and allylamine
to react. The compounds so obtained are united in the followll1g
table in which are also included the finul nitl'ation compollnds
(nitramines) generated from the different pl'oducts. All these nitra-,.mines are of an extremely pale yellow ('olour,
Monoalky I com pounds
Methyl
ethyl
) propyl
isopropyl
lsobuty I
allyl
With
red
yellowish-red
dal'k-red
"
"
yellowish-l'ed
28~0 (witl~
248°.
202 0
2500
1940
208°
"
corresponding
- nitramines
decomp.) 2300 (wlth decomp.)
"
"
"
"
"
2300 I"
213 0
"
209 0
"
2050
"
1000
"
"
"
"
"
"
tin und lIydl'ochlorïc acid the tetl'anitrotetl'l.uneWy l- and
49
Proceedings Royal Acad. Amsterdam. Vol. XVIII.
-4-
760
the tetranitrodimetbyIbenzidine may be l'edueed, also the end nitration
product obtained from these compounds.
As these substances are practically insoluj>le in hydrochloric acid
the reaction pl'oceeds very slowly; the two last named compounds
must be boiled for a considerable time before e\ erything has passed
into solution. On cooling, the lin double salts crystallise in rolonrless
scales. I removed tbe tin with hydrogen slJlphide and on addiug
strong hydrochlorir acid to the fiItrates, 1 obtained the hydrochlorides
of tetraminotetramethyl- and of tetmminodimethylbenzidine in bealltiful, small, colourless neeelles.
The fil'st proeluct begins to elarken at 2400 and decomposes at
251 0 • li contains 4 mols. of hydrogen chloride and 2 mols. of water,
39.4 0 / 0 0 6.7 % H 17.5 % N
Analysis: Found:
17A"
(Jalculated for C1oH32No02014 39.8" 6.6"
The tetramll10dimethylbenzidme whlCh is formeel both from the
tetral1ltrodimethy lbenzidine and from the end product, crystallises
with "'= mols. of hydrogen chloride and 1 mol. of water.
Analysis: Found:
38.8°/fl 6.4%H 19.3 % N
Ualculated foX 014H2oNaOOl4 38.5" 5.8" 19.3"
T happened to succeed in diazotising these amino-compounds and
preparing fl'om the same a number of colouring matters yarying
in shade from red to bluish-violet, by linking them to suitable
substances such as the various naphthylaminosulphonic acids anel
naphtholsulphonic acid. Some of these colouring matters exhibit the
property of dyeing cotton without the aid of a mOl'c1ant.
Further particulal's as to the compounds described in this article
wil! be published before long in the Rec. d. Trav. Chim.
Org. ()hem. Lab. Unive7'sity, Ut1'echt.
Physics. - "On the field of two splterical fixed centres in EINSTEIN' s
the01'y of gmvitation". By J. DROSTE. (Communicated by
Prof. H. A. LORENTZ).
lCommunicated in the meeting of October 30, 1915).
In a former communication 1) I caléulated the field of a single
spherîcal cenü'e and I investigated the motion of a partiele in it.
I now proceed to calculate the field of two fixeel spherical centres
accOl'dmg to the methoel followed by LORENTZ in calculating the
field of a single centre consisting of an incompressible fluid. It
1) Vol. XVII, page 998.
-5-