Note: Descriptions are shown in the official language in which they were submitted.
In the dinitration of an-thraquinone, mixtures are
obtained, as is known, which essentially consist of l,5-. l,8-,
l,6- and l "-dinitroanthraquinone. Various methods for
the separa-tion of such mixtures are described in the literature
With oleum, for example, the separation is carried out accord-
ing to German Offenlegungsschrift (German Publi~hed Specification)
~,143,253, wi-th monohydrate (= 100 ~ stren~th sulphuric acid) it
is carried out according to Helv. chim. Acta 14, 1404 (l93l),
with N-methylpyrrolidone it is carried out according to
~ lO German Offenlegungsschrift 2,334,713, with nitrobenzene
:. it is carried out according to Japanese Laid-open
Published Specification 49-76,~51 and with ni~ro-
benzene and/or nitrotoluene it is carried out according to
German Offenlegungsschrift 2,248,70~.
However, these processes are unsatisfactory with
.. regard to the quality and/or the yield and are actually only
suitable for the isolation of l,5-dinitroanthraquinone, l,5-
dinitroanthraquinone obtained by this separation process still
. containing, however, about 5/0 of l,8-dinitroanthraquinone (com-
pare, for example, German Offenlegungsschrift
. 2,248,/`04).
Such a content of l,8-dinitroanthraquinone in the
l,5-dinitroanthraquinone is very troublesome, however, in the
preparation of secondary products, for example of industrially
important l,5-diamino-anthraquinone and of l-amino-5-benzoyl-
amino-anthraquinone. Thus, in the preparation of l,5-diamino-
anthraquinone, the l,8-dinitroanthraquinone is also reduced and
is -then present in the l,5-diamino-anthraquinone as l,8-diamino-
anthraquinone. During the monobenzoylation reaction, the
l,8-diamino-anthraquinone is converted into l-benzoylamino-8-
aminoanthraquinone and l,8-dibenzoylamino-anthraquinone and is
; Le A ll 371 - 2 -
__
present in this form in -the l-amino-5-benzoylaminoanthraquinone.
The removal of the undesired secondary products of 1,8-dinitro-
anthraquinone can be effected only with difficulty and necessi-
tates complicated and wasteful operations. If the 1,8-
isomeric by-products are not removed, these have a disadvantage-
ous effect on yields and/or shades and/or fastness properties in
the preparation of dyestuffs which are prepared from l-amino-5-
benzoylaminoanthraquinone. Thus as complete a separation as possible
of the 1,8-dinitroan-thraquinone in the 1,5-dinitroanthraquinone
is of great industrial importance.
The separation processes described above are com-
pletely unsuitable for the preparation of pure 1,8-dinitro-
anthraquinone, which is also a valuable dyestuff intermediate
product. Thus, for example, a 1.8-dinitroanthraquinone
which contains 15% of 1,5-dinitroanthraquinone as an impurity is
obtained by the process in German Offenlequnqs~chrift
2,248,7O4.
A process for the separation of dinitroanthraquinone
mixtures using nitrobenzene has now been found, which comprises
the steps of
a) treating I part by weiqht of a dinitroanthraquinone mixture with
4.5-9 parts by weight of nitrobenzene and/or with the solution ob-
tained after the separation of 1,5-dinitroanthraquinone according
to step b) and optionally wash liquid recycled from step b) and/or
with the solution obtained after the separation of 1,X (X = 5, 6,
7 and 8)-dinitroanthraquinone at a temperature of 100 -to 200C and
then separating off the unsoluble constituents at 100 - 150C,
b) treating the residue, which is obtained according to step a)
and essentially consists of 1,5-dinitroanthraquinone, with 1-4 parts
by weight of nitrobenzene at a -temperature from 140C to the boiling
point, then cooling the mixture to 90 to 130C and separating off
Le A 17 371 - 3 -
" and optionally washing wi-th ni-trobenzene the 1,5-dinitroanthra-
quinone which is not dissolved,
c) cooling the solu-tion obtained after the separation of the un-
soluble constituents according to step a) -to 90 to 120C and se-
parating off and optionally washing with nitrobenzene the 1,8-
dinitroanthraquinone which has crystallised out.
The process of the present invention makes possible the
isolation of 1,5-dinitroanthraquinone in purities of over 96 %
with a separation yield of over 80 ~. After separating off
the 1,5-dinitroanthraquinone, 1,8-dinitroanthra~uinone can be
obtained in a similar purity to the 1,5-dinitroanthraquinone.
rn ~eneral, the 1,5-dinitroanthraquinone and 1,8-dinitroanthra-
quinone isolated by the process according to the invention con-
tain less than 2%, often less than 1 %, of the other isomer.
1,5- and 1,8-dinitroanthraquinone of such quality is
certainly obtained when the products separated
off according to steps b) and c) of the inventive process are
washed with nitrobenzene. In cases where the separated products
have a high content of solids, for example more than 70%, espe-
cially more than 80%, products of such purities can also be
obtained often without washing with nitrobenzene.
A preferred embodiment of step a) of the inventive process
comprises one or more of the following process features and can
be carried out, for example, by treating 1 part by weight of a
dinitroanthraquinone mixture with 5.5 to 8 parts by weight of
nitrobenzene at a temperature of 110 to 200C and then separating
off the unsoluble constituents at 110 to 130C.
By heating to a temperature above the temperature at which
the separation is carried out, preferably to a temperature above
Le A 17 371 _ 4 _
: ~
160C, one achieves a considerable coarsening of -the undis-
- solved portions and of those portions which have been precipi~
tated during the cooling; because of this the separation period
and the moisture remaining in the residue (= part of the mother-
liquor) are greatly diminished. After a period of 1/2 - 1 hour
of stirring preferably at 110 to 130C the crystallisation
equilibrium is reached to an extent that these advan-tages are
obtained upon separation. Heating to temperatures above the
temperature at which the separation is carried out one achieves
further a higher content of 1,5-dinitroanthraquinone in -the
separated unsoluble constit-uents and normally a higher purity
of 1,5-dinitroanthraquinone separated in the following step b).
` The residue obtained according to step a), which essentially
consists of 1~5-dinitroanthraquinone, is treated with 2 to 3
parts by weight of nitrobenzene at a temperature of 150 to
`~ 200C, preferably of 160 to 180C, the mixture is then cooled
: to 100 to 110C and the 1,5-dinitroanthraquinone which precipi-
tates is separated off and optionally washed with 0.3 to 1 part
by weight of nitrobenzene.
The solution obtained after separating off the unsoluble
` constituents according to step a) is cooled to 90 to 110C,
preferably to 100 to 110C, and the 1,8-dinitroanthraquinone
which has crystallized out is separated off and optionally
washed with 0.3 to 1 part by weight of nitrobenzene.
The solution obtained after the separation of the 1,8-
optionally combined with the washing liquid from the washing
of 1,8-dinitroanthraquinone is cooled to 5 to 85C, a 1,X-di-
nitroanthraquinone mixture (X - 5, 6, 7 and 8) separating out.
Le A 17 371 - 5 -
:
-. ~
The mixture is separated off and some of the remaining solution
is used again for separating the starting dinitroanthraquinone
mixture employed and some is concentrated by distillation in vacuo
to separate the X,Y-dinltroanthraquinone (X = 5, 6, 7 and 8;
Y = 1 or 2). It is possible to wash the separated 1,X-dinitro-
anthraquinone with nitrobenzene, however, this gives normally
no special advantages because the desired qualities can be ob-
tained without carrying out a washing. It is possible to separate
out the 1,X-dinitroanthraquinone mixture from all of the solution
obtained after the separation of the 1,8-dinitroanthraquinone
or only from a part of this solution. It is possible to isolate
separately the remaining dinitroanthraquinone portions from this
;- solution out of the separation of 1,8-dinitroanthraquinone and
out of the solution obtained after the separation of 1,X-dinitro-
anthraquinone by distilling off nitrobenzene. However, it is
advantageous to work up both solutions jointly by distilling off
nitrobenzene. Dependent from the amount of the solution out
of the separation of 1,8-dinitroanthraquinone which
is used for the isolation of 1,X-dinitroanthraquinone X, Y-
dinitroanthraquinone mixtures of different composition can beobtained. In this manner, further dinitroanthraquinones can
also be obtained, such as 1,6-, 1,7-, 2,6- and 2,7-dinitro-
anthraquinone, in addition to the 1,5- and 1,8-dinitroanthra-
quinone which remained. The temperature to which the solution
out of the 1,8-dinitroanthraquinone separation, optionally to-
gether with the wash liquid from the washing of 1,8-dinitroanthra-
quinone, are cooled is decisive for the composition of -the 1,X-
dinitroanthraquinone mixture obtained. If, for example, the
Le A 17 371 - 6 -
.'
3~
solution is cooled to a -tempera-ture which is above 60 - 70C,
a 1,5- and 1,8-dinitroanthraquinone mixture is obtained which
contains only about 2 to 5% of 1,6- and 1,7-dini-troanthraquinone,
whilst at lower tempera-tures a dinitroanthraquinone mixture is
isolated which can contain up to 40% of 196- and 1,7-dini-tro-
anthraquinone. In the residual solution, some of which, as
mentioned above, can be used again for the separation of the di-
nitroanthraquinone mixture employed, there are the remaining
nitroanthraquinone compounds which have not been separated off,
mainly residual 1,5- and 1,8-dlnitroanthraquinone, in addition
to the majority of the 1,6/1,7-dinitroan-thraquinone contained in
the material employed. This X,Y-dinitroanthraquinone (X = 5,
6, 7 and 8; Y = 1 or 2) can be isolated by distilling off the
- nitrobenzene to dryness, preferably under reduced pressure.
~` 15 When the nitrobenzene used is re-employed in the form of a
part of the solution obtained after separating off 1,X-dinitro-
anthraquinone for the dinitroanthraquinone separation, care mus-t
be taken that no more than 0.25 par-t by weight of dinitroanthra-
quinones, relative to 1 part by weight of the dinitroanthra-
quinone mixture employed, is recycled with the nitrobenzene. The
separations mentioned above, which are separations of solids from
liquids, can be carried out by applying customary methods, for
example by filtration, dekantation or in a hydro-cyclone. The
preferred measures and features stated above can be applied
separately; for example the relative amounts of substances and
temperatures given for a preferred separating operation can be
independent;ly from one another.
It is an essential characteristic of the present invention
that the dinitroanthraquinone mixture employed is initially
3~ pretreated with nitrobenzene, preferably in the form of a
solution obtained after carrying out step b) and/or after sepa-
rating 1,X--dinitroanthraquinone, whilst hot, and -the resulting
Le A 17 37 !
- crude 1,5-dinitroanthraquinone, which still contains about 6
to 30%, preferably 8 to 20%, of 1,8-dinitroanthraquinone, is
again after-treated with pure nitrobenzene. The solution ob-
tained after carrying out step b) can be used in total or par-
tially, the solution obtained after separating 1,X-dinitroanthra-
quinone is preferably partially used for the separation of di-
nitroanthraquinone mixtures. Only by a double treatment with
nitrobenzene, in which the starting dinitroanthraquinone mixture
is also treated with the solution obtained after
carrying out step b), is a 1,5-dinitroanthraquinone obtained
in separation yields of over 80% and purities over 96%, with a 1,8
`~ dinitroanthraquinone proportion of less than 2%, often less
than 1%.
Furthermore, it is important for the process according
to the invention that in the separation of dinitroanthraquinone
mixtures at least about 75%, blt preferably about 80 to 86%, of
the l,5-dinitroanthraquinone presentare separated off before the
l,8-dinitroanthraquinone crystallises ou-t or that, relative
to the l,8-dinitroanthraquinone, only a maximum of 25%, prefer-
ably a maximum of 20%, of l,5-dinitroanthraquinone is sti~l
present. The isolation of l,8-dinitroanthraquinone which
only still contains less than 2% of l,5-dinitroanthraquinone is
otherwise no longer possible or only possible in very low yields.
The recycling, which takes place by the process according
to the invention, of the nitrobenzene solutions obtained in the
1,5- and 1,X-dinitroanthraquinone separation, especially the
recycling of the solution obtained from the fine purification
of 1,5-dinitroanthraquinone and also the recycling of solution
Le A 17 371 - 8 -
,
. .
obtained after the separation of 1,X-dinitroan-
thraquinone~ into the dinitroanthraquinone separation effects
~i- a significant rise in the separation yield in the separation
of 1,5- and 1,8-dinitroanthraquinone. Furthermore, these
~` 5 measures make it possible to carry out the process accor-
ding to the invention particularly economically, since
; only a proportion of the amounts of solvent used must be
-~ purified by distillation.
The dinitroanthraquinone containing mixtures subjected
to the separation process can contain some water,
for example in form of a precipitate obtained in the
dinitration process of anthraquinone after filtration and
washing with water until neutral. Before subjecting such
water containing mixtures to the separation process the
water is to be removed, for example by azeotropic distillation
at normal or reduced pressure. The small amount of nitro-
benzene which distills off together with water is to be replaced
by fresh nitrobenzene. Preferahly the nitrobenzene obtained
after cooling and phase separation of the azeotropic
distillate is used for this purpose. It is also possible to
subject dinitroanthraquinone containing mixtures to the
` separation process which contain up to 2 % by weight of
sulfuric acid without getting worse results with respect to
quality and yield.
Virtually all dinitroanthraquinone mixtures accessible
by industrial routes can be employed in the process acc-rding to
the invention. Thus, for examp e, dinitroanthraquinone
mixtures can be separated which are obtained by the nitration
of an'hraquinone ln highly-concentrated nitric acid, by the
Le A 17 371 - 9 -
.
;
:
nitration of anthraquinone using a mixture of highly-
concentrated nitric acid and 0.75 to 2 parts hy weight of
sulphuric acid, relative to the weigl1t of nitric acid,
or by thc nitration of anthraquinone in exces~ sulphuric
acid, which optionally contains S03, or hydrofluoric
acid or organic solvents. It is also possible
te cmploy those dini-tration products which have bcen
obtained by the nitration of 1-nitroanthraquinone, which
may contain other nitroanthraquinones as impurities.
The 1-nitroanthraquinone to be nitrated can contain anthra-
quinone, 2-nitroanthraquinone and the various dinitro-
anthraquinone isomers as impurities, especially if it has
been obtained as the residual product in the purification
of 1-nitroanthraquinone by crystallisa-tion or distillation.
Furthermore, those dinitroanthraquinone mixtures which
are obtained by mixing any desired products, solutions or
suspensions of any desired origin eontaining 1,5- and 1,8-
dinitroanthraquinone ean also be employed in the process
aeeording to the invention. The eontent of any 1,6- and
1,7-dinitroanthraquinone whieh may be present and the ratio
of 1,5-dinitroanthraquinone to 1,8 dinitroanthraquinone are
of minor importanee.
The proeess aeeording to the invention ean be earried
out both diseontinuously and partly or entirely eontinuously.
Le ~ 17 371 - 10
-~ . .
Th- 1,5- and 1,8-dinitroanthraqui~one obtained according to the
inve~tion can be con~erted directly into the correspon~ing
amino compoun,1 and then further processed to giv~ anthraquinone
~- dyest,lffs 'compare, for example, Friedlaender, Fortschri-tte
der Teerfarben-Fabri]iation (~dvances in the Manufacture of
Aniline Dyes), 22nd part(1935), page 1014; Fiat Final Report 1313,
German Dyestuffs and Interm~diates, II, page 26).
The examples which follow are intend-d to illus ra~e
further the process according to the invenlion. The
- 10 analyses in the examples are based ~n high pressure liquidchroDatogiaplly and on semi-qua;ltitative thin layer chromatography.
Examples
s 1. Separation of a dinitroanthraquinone mixture having the
composition: 0.5% of 2,6-dinitroanthraquinone, 0.4 % of 2,7-
15 dinitro~nthraquinone, 1.8% of l-nitroan~hraqlinone, 9.8% of
1,6-dinitroanthraqlinone, 9.6% of l,l-dinitroanthraquin~ne,
. 33 9~ of 1,5-dinitroanthraquinone and 36.6% of 1,8-dinitro-
anthraquinone, obtained during the nitration of 20~ g of anthra-
quinone with a mixture of 424 g of 98% strength nitric acid and
500 g of sulphuric acid monohydrate, the mixture having been
stirred initially at 4~C (l an hour), then at 50C (-1- an hour).
The instructions which follow refer to a crystallisation
with recycling of -the mother liquor after all the crystallisation
- e~uilibria are established For starting up, pure nitrobenzene is
used instead of recycled mother liquor.
1.1 Isolation of -the 1,5-dinitroanthraquinone
65.0 ~ of the above dinitroanthr~quinone mixture to~ether
with 252 g of recycled mother liquor from 1.3. and 252 q of re-
cycled mother-liquor from the fine purification described below
30 are warmed to 120~C for 0.5 hours, whilst stirring, and the mix-
ture is then filtered a-t 120C. The fil-trate is used for
Le A 17 371 - 11 -
further pro~essing -to give 1,8-dinitroanthraquinone according
to 1.2 The moist filter cake is war~ed to 160C with
18~ g of ~itrobenzene for 0.5 hour , whilst stirring. The
mixture is then cooled to 10~C in the course o~ 0.2~ hour, and
after stirring for 0.5 hour at 100C, is fil-tered. The
residue is was'~ed with 60 g of nitrobenzene, heated to 10~C,
in portions. The combined filtrates of the fine pariflca-
tion which still con-tain dissolved dinitroanthraquinorle and/o~
mononitroanthraquinone are used for the next 1,5-dinitroanthra-
q~inone cry~tallis~tion After drying the residue in vacuo atlOnC, the~ are obtained.22 4 g of 1,5-dinitro~nthraquinone (97.7
-~ of l,~-dinitroanthraquinone, 1 1% of 1,8-dinitroanthraquinone,
0.2~ of 1,6-dinitroanthraquinone and 0.1% of l,~-dinitroantnra-
quinone).
Separation yield 84.1%.
., .
1 2. Isolation of the 1,8-dinitroanthraquinone
The filtrate from the 1,5-dinitroanthraquinone separa-
;'~ tion (about 510 g) is cooled to 105C, after it has been warmed,
if appropriate, to 140C in order to achieve a clear solu~ion,
and seeded with a few rystals of 1,8-dinitroanthraquinone and
the mixture is stirred for 2 hours at 105C. It is filtered
and the residue is washed with 48 g of cold nitrobenzene and
dried in vacuo at 100C: 7.3 g of 1,8-dinitroanthraquinone
(98 5% of 1,8-dinitroanthraquinone an-l ).6% of i,5--dinitro-
anthraquinone).
Separa-~jon yield 30,2%.
The combined filtrates are used for the separation of
the l,X-dinitroanthraquinone mixture according to 1.3.
1.3. Isolation of the l,X-dinitroanthraquinone (X = 5,6, 7 and 8)
The combined filtrates from the 1,8-dinitroanthraquinone
separation (about 540 g) are warmed to 120C until the solution
Le A 17 371 _ 12 -
. .
32
becomes clear. It is then cooled to 25C and stirred atthis temperature for 3 hours. The product which has
~; crystallised out is then filtered off and dried in vacuo at
100C: 21.0 g of l,X-dinitroanthraquinone (6.'/% of 1,6-di-
nitroanthraquinone, 15.6% of l,','-dinitroanthraquinone, 10.8%
of 1,5-dinitroanthraquinone and 60.','% of 1,8-dini-troanthra-
'~ quinone and 2.2% of l-nitroanthraquinone).
1.4. Isolation of the X,Y-dinitroanthraquinone (Y=l and 2, X =
' 5, 6, ',' and 8)
The filtrate from 1.3. (about 504 g) is divided, about
252 g being recycled to 1.1 for the next crystallis-
ation. The remainder is distilled to dryness in vacuo:
11.1 g of X,Y-dinitroanthraquinone (2.0% of 2,6-dinitroanthra-
quinone, 1.9% of 2,'7-dinitroanthraquinone, 3r7 ~ 5% of 1,6-dinitro-
anthraquinone, 22.1% of l,~-dinitroan-thraquinone, 6.1% of 1,5-
; dinitroanthraquinone and 14.4% of 1,8-dinitroanthraquinone and
~' 3.6% of l-nitroanthraquinone).
The nitrobenzene which has distilled off is used again
" in 1.1. and 1.2.
2. Separation of a dinitroanthraquinone mixture having
~` the composition of Example 1 (for establishing the crystallisat-
ion equilibria, compare Example 1).
2.1. Isolation of the 1,5-dinitroanthraquinone
65.0 g of the dinitroanthraquinone mixture having the
composition as in Example 1, together with 216 g of nitrobenzene
and 252 g oE recycled Eiltra-te an~ ~Jashing liquid Erom the fine purification
described below,are warmed to 120C for 0.5 hour, whilst
stirring, and the mixture is then filtered at 120C. The
filtrate is used for the further processing to give 1,8-dinitro-
anthraquinone according to 2.2. The moist residue iswarmed -to 180C with 180 g of nitrobenzene for 0.5 hour, whilst
Le A 17 371 - 1~-
stirring The mixture is then cooled to 100C in -the
- course of 025 hour and, after stirring for 0.5 hour at 100C,
the product which has crystallised out is filtered off. The
material on the filter is washed with 60 g of hot nitrobenzene
in portions. The combined filtrates of this fine purifica-
- tion are used for the next 1,5-dinitroanthraquinone crystallisa-
tion. After drying the residue in vacuo at 100C, there
are obtained: 21., g of 1,5-dinitroanthraquinone (98.8% of 1,5
dinitroanthraquinone and 1.1% of 1,8-dinitroanthraquinone).
- 10 Separation yield 82.f%.
2.2. Isolation of the 1,8-dinitroanthraquinone
` The filtrate from 2.1. is cooled to 100C and stirred a-t
100C for 2 hours. The crystals are filtered off, washed
with 48 g of nitrobenzene and dried in vacuo at 100C: 6.8 g
of 1,8-dinitroanthraquinone (9/.5% of 1,8-dinitroanthraquinone
and 0.1% of 1,5-dinitroanthraquinone).
; Separation yield 2-7.9%.
2.3. Isolation of the l,X-dinitroanthraquinone (X = 5, 6, I
and 8)
The combined filtrates from the 1,8-dinitroanthraquinone
separation are cooled to 25C and stirred for 3 hours at this
temperature. The precipitate is then filtered off and dried
at 100C in vacuo: 16.1 g of l,X-dinitroanthraquinone (2.6% of
1,6-dinitroanthraquinone, 4.9% of 1,7-dinitroanthraquinone,
12.6% of 1,5-dinitroanthraquinone and 74.4% of 1,8-dinitroanthra-
quinone).
2.4. Isolation of the X,Y-dini-troanthraquinone (Y = 1 and 2,
X = 5,6, l and 8)
The filtrate from 2.3. is distilled to dryness in vacuo:
19.5 g of X,Y-dinitroanthraquinone (1.5% of 2,6-dinitroanthra-
quinone, 1.5% of 2,7-dinitroanthraquinone, 30.8% of 1,6-dinitro-
Le A 17 ~71 - 14 -
-
anthraquinone, 28,2% of l"'-dinitroanthraquinone, 7.8% of 1,5-
dinitroanthraquinone and 16.1% of 1,8-dini-troanthraquinone and
4.2% of l-nitroan-thraquinone).
' The nitrobenzene which has distilled off can be used
again in 2.1. and 2.2.
` ;. Separation of a dinitroanthraquinone mixture having the
~' composition: 0.4% of 2,6-dinitroanthraquinone, 0.5% of 2,7-
,~ dinitroanthraquinone, 1.','% of l-nitroanthraquinone, 10.6% of
~..
1,6-dinitroanthraquinone, 10.8% of l,'~-dinitroanthraquinone,
:6.5% o~ 1,5-dinitroanthraquinone, ~4.7% of 1,8-dinitroanthra-
, quinone and 0,1% of anthraquinone, obtained during the nitration
' of 188 g of anthraquinone, 145 g of a mother liquor product of a
l-nitroanthraquinone pre-purification and 87 g of a distillation
- residue from a l-nitroanthraquinone distillation (composition of
: 15 the mixture: 48,4% of anthraquinone, 5.5% of 1,5~dinitroanthra-
quinone, 5,1% of 1,8-dinitroanthraquinone, 1,5% of l,'l-dinitro-
anthraquinone and 1,4% of 1,6-dinitroanthraquinone, 26.7% of 1-
nitroanthraquinone and ~.1% of 2-nitroanthraquinone) wi-th 62'l g
of 98% strength nitric acid and '102 g of 96% strength sulphuric
acid at temperatures of ~0C (1- an hour), which were then raised
to 50C (~ an hour) and 60C (1 an hour),
The instructions which follow refer to a crystallisation
with nitrobenzene recycling after all the equilibria are
established, For startin~ u~ pure nitrobenzene is used ins-tead
of recycled mother liquor.
~,1, Isolation of the 1,5-dinitroanthraquinone
70.7 g of the above dinitroanthraquinone mixture together
with 252 g of recycled filtrate and wash liquid from the fine purification
of 1,5-dinitroanthraquinone described further below, 72 g of
; 30 pure nitrobenzene and 180 g of recycled filtrate from 3.3
are warmed to 120C for 1 hour, whilst stirring, and the mixture
Le A 17 371 _ 15 _
is then filtered at 120C. The ~iltrate is used for the
further processing to give 1,8-dinitroanthraquinone according
to 3.2. The moist fil-ter cake is warmed to 180C with
180 g of nitrobenzene for 0.5 hour, whilst stirring, the mix-ture
, is then cooled to 100C and filtered after stirring for -~ an
hour at 100C and the residue is washed with 60 g of nitro-
benzene, heated to 100C, in portions, and dried at 100C.
rl`~lere are obtained: 22.9 g of 1,5-dinitroanthraquinone (9/ 8%
of 1,5-dinitroanthraquinone, 1.8% of 1,8-dini-troanthraquinone
- 10 and 0.~% of l-nitroanthraquinone).
Separation yield 86.8%.
-~.2. Isolation of the 1,8-dinitroanthraquinone
In this process, in the manner described in Example
1.2., the filtrate from 3.1. is crystallised at 100-102C and
the crystals are then worked up: 9.5 g of 1,8-dinitroanthra-
quinone (9,`.8% of 1,8-dinitroanthraquinone and 0 3% of 1,5-
` dinitroanthraquinone)
Separation yield 38%.
The combined filtrates are used for the separation,
according to 3.3., of a l,X-dinitroanthraquinone mixture.
3 3 Isolation of the l,X-dinitroanthraquinone (X = 5, 6, 7
and 8)
The combined filtrates from the 1,8-dinitroanthraquinone
separation in 3 2. are stirred at 60C for 3 hours, after they
had been brought into solution again by warming briefly to
~` lS0C The precipitate is then filtered off and dried at
100C: 13 2 g of l,X-dinitroanthraquinone (1.5% of l-nitro-
anthraquinone, 2 1% of 1,6-dinitroanthraquinone, 4.0% of 1,7-
dinitroanthraquinone, 16 9% of 1,5-dinitroanthraquinone and
7S.3% of lJ8-dinitroanthraquinone).
3.4 Isolation of the X,Y-dinitroanthraquinone (Y = 1 and 2,
Le A 17 37]; - 16 -
-`~
`,:
` X = 5, 6, 7 and 8)
Af-ter separa-tlng off 180 g for recycling -to
-i.l., the fil-trate from ~ 3 is dis-tilled to dryness.
;:
21.9 g of X,Y-dinitroanthraquinone (~ 8% of l-nitro-
anthraquinone, l.2% of 2,6-dinitroanthraquinone, l 3% of 2,7-
dinitroanthraquinone, ~0.7% of l,6-dinitroanthraquinone 7 26.2%
of l" -dinitroanthraquinone, 5 5% of l,5-dinitroanthraquinone and
2l.2~o of l,8-dinitroanthraquinone).
4. Separation of a dinitroanthraquinone mix-ture having the
composition: 0.5% of 2,6-dinitroanthraquinone, 0.4% of 2,7-
dinitroanthraquinone, l.2% of l-nitroanthraquinone, lO.3% of
l,6-dinitroanthraquinone, lO.2% of l,l-dinitroanthraquinone,
38.1% of l,5-dinitroanthraquinone, 34.60/o of l~8-dinitroanthra-
quinone and 0.1% of anthraquinone, obtained after nitrating a
mixture of ,`2.6 g of anthraquinone, 56.1 g of the mother liquor
product of a l-nitroanthraquinone pre-purification, 31.l g of
the sump product of a l-nitroanthraquinone distillation having
the composition: (48.3% of anthraquinone, 5.2% of l,5-dinitro-
anthraquinone, 5.6% of l,8-dinitroanthraquinone, l.3% of l,6-
dinitroanthraquinone, l.4% of l,l-dinitroanthraquinone, 26.7%
of l-nitroanthraquinone, 9.9% of 2-nitroanthraquinone and 0.5%
of 2,6- and 2 "-dinitroanthraquinone) with 226 ml of nitric acid
(98% strength) and 213 ml of sulphuric acid (85% strength) a-t
an initial temperature of 30C (l hour), which was then
increased to 40C (l hour) and to 50C (2 hours).
The instructions which follow refer to a crystallisation
with filtrate recycling aEter all the equilibria are
establishecl.For starting up, pure nitrobenzene is used instead
of recyclecl filtrate.
4.l. Iso].ation of the l,5-dinitroanthraquinone
70,7 g of the above dinitroanthraquinone mixture toge-ther
Le A 17 37~ - 17 - ~
with 252 g of recycled filtrate from the fine purification
of the 1,5-dinitroanthraquinone described further below and
256 ~ of recycled moth~r liquor from ~.3 are warmed to
120C ror 1 hour, whilst stirrin~, and the
mixture is then filtered at 120~C. The filtrate is used
for the further processing to give l,8-dinitroanthraquinone
. according to 4.2. The moist filter cake is warmed to 180C
with 180 g of nitrobenzene for 5 hours, whilst stirring, and
then cooled to 100C and, after stirring at 100C for l an
hour, the precipitate is filtered off, washed wi-th 60 g of
nitrobenzene, heated to 100C, in portions and dried at 100C.
There are obtained: 2~.3 g of 1,5-dinitroanthraquinone (97.6%
of 1,5-dinitroanthraquinone, 1.~% of 1,8-dinitroanthraquinone
and 0.3% of l-nitroanthraquinone).
Separation yield 84.4%.
4.2, Isolation of the 1,8-dinitroanthraquinone
In this process, in the manner described in Example 1.2.,
the filtrate from 4.1. is crystallised at 95C in the course of
6 hours and then worked up: 11.l g of 1,8-dinitroan-thraquinone
(98.0~ of 1,8- and 1,3 ~ of 1,5-dinitroanthraquinone).
Separation yield 46.9%.
The combined filtrates are used for the separation,
according to 4.3., of a l,X-dinitroanthraquinone mixture.
4.3. Isolation of the l,X-dinitroanthraquinone (X = 5, 6, 7
and 8)
The combined filtrates from the 1,8-dinitroanthraquinone
separation in 4.2. are stirred at 25C for 5 hours after they
had been brought into solution again by briefly warming to 130C.
The precipitate is then filtered off and dried at 100C: 21.0 g
of l,X-dinitroanthraquinone (1 8% of l-nitroanthraquinone,
11.9% of 1,6-dinitroanthraquinone, 22.8% of 1,7-dinitroanthra-
Le A 17 37I - 18 -
,' , : .
' ~ ' ' ' - ' ; '.
: `
quinone, 1~.1% of 1,5-dini-troanthraquinone and 4'/.f% of 1,8-
dinitroanthraquinone).
About half of the filtrate (about 256 g) is recycled
to 4.1.
.4. Isolation of the X,Y-dinitroanthraquinone (Y = 1 and 2,
X = 5, 6, '7 and 8)
:
` The remaining filtrat;e from 4.~. is distilled to dry-
ness in vacuo at 150C: 12.5 g of X,Y-dinitroanthraquinone
:
- (2.~% of l-nitroanthraquinone, 1.8% of 2,6-dinitroanthraquinone,
. ~ lQ 1.1% of 2,''-dinitroanthraquinone, 36.~% of 1,6-dinitroanthra-
' quinone, 19.0% of l,~-dinitroanthraquinone, 6.2% of 1,5-di-
: nitroanthraquinone and 15.1% of 1,8-dinitroanthraquinone).
- 5. Separation of a dinitroanthraquinone mixture having -the
composition: 0.4% of 2,6-dinitroanthraquinone, 0.4% of 2,~-
dinitroanthraquinone, 1.7% of l-nitroanthraquinone, 10.6% of
1,6-dinitroanthraquinone, 10.8% of 1,1-dinitroanthraquinone,
36.~% of 1,5-dinitroanthraquinone, 34.'1% of 1,8-dinitroanthra-
quinone and 0.10% of an-thraquinone, obtained according to the
nitration instructions given in Example 3.
; 20 The instructions which follow refer to a crystallisation
with filtrate recyclin~ after all the equilibria are
established.For starting up, pure nitrobenzene is used instead
of recycled filtrate.
5.1. Isolation of the 1,5-dinitroanthraquinone
'70.7 g of the above dinitroanthraquinone mixture together
~: with 260 ~ of recycled filtrate from the fine purification
of the 1,5-dinitroanthraquinone described further below and
73 ~ of recycled filtrate from 5.3. are warmed to 170C for 1
hour, cooled to 120 C, stirred for 1 hour 120C and the mixture
is then filtered at 120C. The filtrate is used for the further
processing to give 1,8-dinitroanthraquinone according to 5.2. The
Le A 1? 371 - 1 9
moist filter cake is warmed to 160~C with 180 g of nitro-
benzene for 0.5 hour, whilst stirring, the mixture is then
cooled to 100C and, af-ter stirring at 100C for 1/2 an hour,
- -the precipitate is sharply succed off, and dried at 100C.
5 There are obtained: 22.5 g of 1,5-dinitroanthraquinone
(97.6 % of 1,5-dinitroanthraquinone, 0.8 % of 1,8-dinitro-
anthraquinone and 0.3 % of 1-nitroanthraquinone.
Separation yield 85.-L%.
5.2 Isolation of the 1,8-dinitroanthraquinone
The filtrate from the 1,5-dinitroanthraquinone separa-
tion is warmed to 1~0C with 183 q of recycled filtrate
from 5.3., ~hilst stirring, until a clear solution is obtained
and the solution is then cooled to 100C and allowed to
crystallise out in the course of 1.5 hours. The
crystals are filtered off, sharply succed and
dried at 120C: 9.0 g of 1,8-dinitroanthraquinone (98.2% pure~
containing 1.0% of 1,5-dinitroanthraquinone, 0.3% of 1,6-
dinitroanthraquinone and 0.3% of 1,7-dini-troanthraquinone).
Separation yield 36 1%
` The combined filtrates are used for the separation,
according to 5 3., of the l,X-dinitroanthraquinone mixture.
; 5.3. Isolation of the l,X-dinitroanthraquinone (X = 5, 6, 7
and 8)
The filtrates from 5.2. are cooled -to 10C and s-tirred
at this temperature for 3 hours. The precipitate is then
; filtered off and dried in vacuo: 28.6 g of l,X-dinitroanthra-
quinone containing l,8-dinitroanthraquinone as the main com-
ponent (50-60%) and 5-10% of 1,5-dinitroanthraquinone, 20-25%
of 1,7-dinitroanthraquinone and about 15% of 1,6-dinitroan-thra-
quinone.
Le A 17 371 - 20 -
,,
About half o~ the filtrate is recycled to
5 1 and 5.2.
6. 1,5- and 1,8-dinitroanthraquinone can be obtained
in very si~ilar qualities and with very similar separation yields,
iE Example 4 is repeated, however using instead of 70.7 g
dinitroanthraquinone of the given composition
; a) 76 ~ of a dinitroanthraquinone mixture of followinq compo-
sition: 0.7 ~ 2,6-; 0.7 % 2,7-; 12.9 % 1,6-; 12.6 ~ 1.7-;
35.3 ~ 1.5-; 32.6 % 1,8-dinitroanthraquinone and 1.4 ~ 1-nitro-
anthraquinone.
Such a dinitroanthraquinone mixture can be obtained as follows:
A mixture containing 7 % anthraquinone, 9.8 % 1,5-, 9.2 ~ 1,8-,
2.7 % 1,6-, 2.7 % 1,7-dinitroanthraquinone, 48.4 % 1~ and 16.4 %
2-nitroanthraquinone is nitrated with a mixed acid consisting
of the 1.23 fold amount by weight of 98 % nitric acid and
the 1.4 fold amount by weight of 96 % sulfuric acid at 40, 50
and 60C (each temperature is maintained for 30 minutes). After
dilution with water the nitration product is isolated in customary
manner. The starting material for such nitration can be obtained
by mixing the product obtained in the working up of the mother
liquor of the purification of 1-nitroanthraquinone by crystallisation
and the product obtained as residue in the distillation of
1-nitroanthraquinone.
b) 61.2 g of a dinitroanthraquinone mixture of following
composition: 2 % 1-nitroanthraquinone, 3.4 % 1,6-, 3.5 ~ 1,7-,
47.2 % 1,5- and 39.1 % 1,8-dinitroanthraquinone.
` Such a dinitroanthraquinone mixture can be obtained as follows:
A mixture containing 20.5 % 1,5-, 13.9 % 1,8-, 0.5 ~ 1,6-,
0.4 ~ 1.7-dinitroanthraquinone, 59.8 ~ 1- and 0.1 % 2-nitro-
anthraquinone is nitrated with a mixed acid consisting of the
Le A 17 37:L j - 21 -
?
3~
" 1.4 fold amount by weight of 98 % nitric acid and of the 1.67
fold amount by wei~ht of 96 % sulfuric acid at 40, 50 and 60C
(cach temperature is maintained for 30 ~inutes). Af-ter dilution
with water the nitration product is isolated in cus-tomary
manner. The startinq material for such ni-tration can be obtained
as a residue in the distillation of 1-nitroanthraquinone.
c) 8.15 g of a dinitroanthraquinone mixture of followin~
composition: 1.0 % 1-nitroanthraquinone, 1.3 ~ 2,7-, 1.1 %
2,6-, 18.4 % 1,6-, 17.9 % 1,7-, 27.9 % 1,5- and 28.7 % 1,8-
dinitroanthraq~inone.
Such a dinitroanthraquinone mixture can be obtained asfollows: ~ mixture containing 11.2 ~ anthraquinone, 3.4 %
1,5-, 6.4 % 1,8-, 4 % l,6-, 4 % 1,7-dinitroanthraquinone,
41.4 % 1- and 26.2 % 2-nitroanthraquinone is nitrated with a
mixed acid consisting of the 1.4 fold amount by weight of 98 %
nitric acid and the 1.67 fold amount by weight of 96 % sulEuric
acid at 40, 50 and 60C (each temperature is maintained for
30 minutes). After dilution with water the nitration product
is isolated in customary manner. The startin~ material for such
nitration can be obtained in the working up of the mother liquor of
the pre-purification of 1-nitroanthraquinone by crystallisation.
7. Separation of a dinitroanthraquinone mixture having the
composition: 0.4 % of 2,6-dini-troanthraquinone, 0.4 % of 2,7-
dinitroanthraquinone, 1.7 % of 1-nitroanthraquinone, 10.6 % of
1,6 dinitroanthraquinone, 10.8 % of 1,7-dinitroanthraquinone,
36.5 % of 1,5-dinitroanthraquinone, 34,7 % of 1,8-dinitroanthra-
quinone and 0.10 % of anthraquinone, obtained according to the
nitration instructions given in Example 3.
The instructions which follow refer to a crystallisa-tion
with recycling of mother liquor after all the equilibria are
Le A 17 371 - 22 -
.
$~ 3~
:
established. Fc>r starting up, pure nitrohenzene is used ins-tead
of recycled mother-liquor.
7.1 rsolation of the 1,5-dinitroan-thraquinone
70.7 g of the above dinitroanthraquinone mixture together
with 247 g of recycled mother-liquor from the fine purification
of the 1,5-dinitroan-thraquinone described further below and
- all of the mother-liquor from 7.3. are warmed to 180C for
3 hours, whilst stirring, then cooled to 120C during 30 minutes
by means of vaporization cooling of nitrobenzene at reduced
pressure, then stirred for 1 hour at 120C. The mixture is then
filtered at 120C. The filtrate is used for the further processing
to give 1,8-dinitroanthraquinone according to 7.2. The moist
filter cake is warmed to 160 C with 180 g of nitrobenzene for
0.5 hour, whilst stirring, the mixture is then cooled to 100C
and, after stirring at 100C for 1/2 an hour, the precipitate
is filtered off, washed with 60 g of cold nitrobenzene in portions,
and dried at 100C. There are obtained: 22.4 g of 1,5-dinitro-
anthraquinone (98~9% of 1,5-dinitroanthraquinone, 0.6% of
1,8-dinitroanthraquinone and 0.1 % of 1-nitroanthraquinone).
Separation yield 85. 9 %
7.2 Isolation of the 1,8-dinitroanthraquinone
The filtrate from the 1,5-dinitroanthraquinone separation
is warmed -to 140C whilst stirring, until a clear solution is
obtained and the solution is then cooled to 100C and allowed to
crystallize out in the course of 1.5 hours. The crystals
are filtered off, washed with 48 g of cold nitrobenzene and
dried at 120C: 8.3 g of 1,8-dinitroanthraquinone (97.4 % pure,
containing 0.8 % of 1,5-dinitroanthraquinone, 0.4 % of 1,6-
dinitroanthxaquinone and 0.5 ~6 of 1,7-dinitroanthraquinone).
Separation yield 82.9 %.
Le A 17 371 - 23
,
32
part of the combined filtrates are used for the separation,
accordir.g to 7.3., of the l,X-dinitroanthraquinone mixture.
7.3. Isolation of the l,X-clinitroanthraquinone (X = 5, 6, 7
and 8)
Half of the filtrates from 7.3 ~about 200 g) are cooled to 60C
and stirred at this temperature for 3 hours. Tlle precipitate
is then filtered off and dried in vacuo: 9.5 g of l,X-dinitro-
anthraquinone containing 64.6 % og 1,8-dinitroanthraquinone and
13.5 % of 1,5-dinitroanthraquinone, 13.0 % of 1,7-dinitroanthra-
quinone and about 4.1 % of 1,6-dinitroan-thra~uinone.
: 7.4 Isolation of X, Y-dinitroanthraquinone (X = 1 and 2,
Y = 5, 6, 7 and 8).
Half of the filtrate from 7.2 is freed of nitrobenzene in vacuo:
30.0 g X, Y-dinitroanthraquinone cor.taining 30.9 % of 1,8-,
8.3 ~ of 1.5-, 21.2 ~ cf 1,7-, 24.4 ~ of 1,6-, 1 ~ 2,6-,
1 ~ 2,7-dlnitroanthraquinone and 2.7 ~ 1-nitroanthr~quinone.
`:
.
Le A 17 371 - 24 -
