Process for Preparing Diazotisable and Non-diazotisable Com- pounds by Means of Primary Aromatic Monamines and Aromatic Diamines, and the Manufacture of Colouring Matters derived therefrom.
Year: 1898

page_text: 3
Date of Application, 23rd Apr., 1898
La COLL
1000
1414
1000
Date of Application, GUTU APT., 1000
Complete Specification Left, 20th Jan., 1999 Accepted, 14th Mar., 1000
PROVISIONAL SPECIFICATION.
A Process for Preparing Diazotisable and Non-diazotisable Com-
pounds by Means of Primary Aromatic Monamines and Aromatic
Diamines, and the Manufacture of Colouring Matters derived
therefrom.
I, MAURICE PRUD'HOMME, of 105, Rue Lafayette, Paris, France, Chemist, do
hereby declare the nature of this invention to be as follows;-
I have previously shewn that it is possible to convert simple amido-basic
colouring matters, such as reds and the like, into acid colouring matters by the
combined action of formaldehyde and sodium bisulphite. I have now found that
an analogous reaction can be applied to aromatic primary amines with teclinical
results which differ accordingly as the reaction is applied to aromatic primary
monamines or to aromatic diamines of the same kind.
Generally speaking, aromatic primary monamines, like aniline and a-naphthyl-
amine, when treated with formaldehyde and sodium bisulphite or sulphurous
acid yield new compounds which are soluble in alkalies and are not diazotisable;
on the contrary, aromatic diamines, such as meta- or para-phenylenediamine hen-
zidine, tolidine, azoxytoluidine, dianisidine and the like, under the same conditions,
yield new complex compounds which are still diazotisable and are soluble in
alkalies. In determining the proportions it is to be remarked that the diazotis-
ability of these latter new compounds is only one half of that of the parent com-
pound; that is to say, one molecular proportion of benzidine which originally
required two molecular proportions of sodium nitrite for complete diazotisation
only requires one molecular proportion after the treatment.
General examples of the conversion of primary amines into new compounds,
diazotisable or not, and soluble in alkalies, are as follows;-
EXAMPLE I.
The naphthylamine hydrochloride obtained by treating 143 kilos of a-naphthyl-
amine with 400 kilos of commercial hydrochloric acid is dissolved in 10,000
litres of water, the solution is heated to from 70° to 75° C. and there is added,
without continuing to heat, a solution of 150 kilos of commercial formaldehyde
of 40 per cent. strength and 600 kilos of sodium bisulphite solution of specific
gravity 38° Baumé. The whole is allowed to cool and is filtered the residue
being washed on the filter. The yellowish precipitate thus obtained is entirely
soluble in alkalies; it cannot be diazotised but becomes slightly coloured on the
addition of some drops of sodium nitrite.
EXAMPLE II

page_text: dissolved in 10,000 litres of water, the solution is heated to from 70° to 75° C.
and without continuing to heat there is added a solution of 150 kilos of commer-
cial formaldehyde of 40 per cent. strength and 600 kilos of sodium bisulphite
solution of specific gravity 38° Baumé the whole is allowed to cool and is fil-
tered. The precipitate thus obtained is in the form of a creamy bluish white
mass, insoluble in water but soluble in alkalies; from the alkaline solutions the
original compound is precipitated by the addition of acid.
If the operation has been properly conducted the filtered liquor will rarely
contain unchanged benzidine and will very rarely yield a precipitate on the addi-
tion of sulphate or of sulphuric acid or of caustic soda.
In the Example 11. an equi-molecular proportion of tolidine, ethoxy- or meth-
oxy-benzidine, dianisidine, para- or meta-phenylenediamine, azoxyaniline er
azoxytoluidine or the like may be substituted for the benzidine.
The new compounds derived from the diamines are clearly differentiated from
the parent diamines by the following characteristics:-
Insolubility in acids such as hydrochloric acid and the like.
Solubility in alkalies and precipitation from these solutions by acids, and
Capacity for diazotisation exactly one half of that of the parent diamines.
When to these characteristics is added this one, namely that the diazo-
derivatives of these new compounds combine with amines or phenols not sulpho-
nated, yielding azo-colouring matters which are very soluble in water, while the
parent diamines yield colouring matters which are insoluble or very little soluble,
it may be concluded that the new compounds are either sulphonated or sulphi-
nated.
EXAMPLE III.
3.75 kilos of the compound obtained in Example II., that is to say by the
action of sodium bisulphite and formaldehyde on benzidine, are dissolved in a
little dilute soda lye and there are added 710 grams of sodium nitrite, a slight
excess of commercial hydrochloric acid, about 2.5 kilos, and ice to keep the tem-
perature in the vicinity of from 5° to 10° C; after an hour the mixture is poured
into an alkaline solution of about 2.6 kilos of the sodium naphthol disulphonate
(R. salt). The mixture is allowed to stand for some hours, during which time it
is stirred, and the colouring matter is precipitated.
There is thus obtained a violet-blue colouring matter.
With Piria's naphthionic acid there is obtained an orange colouring matter,
with Schaeffer's salt a garnet-coloured colouring matter; with R salt a blue
violet coloured colouring matter; with G salt a yellowish garnet-coloured colour-
ing matter with amidonaphthol G a black colouring matter; with H salt a blue
colouring matter; with chromotrope acid a violet colouring matter; with salicylic
acid a green yellow colouring matter.
In Example III. tolidine, dianisidine, methoxy- or ethoxy-benzidine, para- or
meta-phenylenediamine, azoxyaniline or azoxytoluidine from the nitrotoluidine
which melts at 107° C. may be substituted for the benzidine.
With azoxytoluidine the R salt yields a very bright poppy-red colour.
On wool, with azoxytoluidine, N.W. salt also gives a poppy-red colour,
Schaeffer's salt a very red orange and G salt a fine orange.
All the colouring matters are very soluble in water and generally difficultly
precipitable by common salt: they dye wool in an acid bath very well and cotton
in a neutral or alkaline bath a little less well than do the colouring matters.
derived from the unchanged diamines.
Dated this 23rd day of April 1898,
ABEL & IMRAY,
Agents for the Applicant.

page_text: A Process for Preparing Diazotisable and Non-diazotisable Com-
pounds by Means of Primary Aromatic Monamines and Aromatic
Diamines, and the Manufacture of Colouring Matters derived
therefrom.
I, MAURICE PRUD'HOMME, of 105, Rue Lafayette, Paris, France, Chemist, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the follow-
ing statement-
I have previously shewn that it is possible to convert simple amido-basic
colouring matters, such as reds and the like, into acid colouring matters by the
combine action of formaldehyde and sodium bisulphite. I have now found that
an analogous reaction can be applied to aromatic primary amines with technical
results which differ accordingly as the reaction is applied to aromatic primary
monamines or to aromatic diamines of the same kind.
Generally speaking aromatic primary monamines, like aniline and a-naphthyl-
amine, when treated with formaldehyde and sodium bisulphite or sulphurous
acid yield new compounds which are soluble in alkalies and insoluble in water,
except that from aniline which is soluble in water, and are not diazotisable; on
the contrary aromatic diamines, such as meta- or para-phenylenediamine, benzi-
dine, tolidine, azoxytoluidine, dianisidine and the like, under the same conditions,
yield new complex compounds which are still diazotisable and are soluble in
alkalies. In determining the proportions it is to be remarked that the diazotis-
ability of these latter new compounds is only one half of that of the parent com-
pound; that is to say, one molecular proportion of benzidine which originally
required two molecular proportions of sodium nitrite for complete diazotisation
only requires one molecular proportion after the treatment.
General examples of the conversion of primary amines into new compounds,
diazotisable or not, and soluble in alkalies, are as follows:-
EXAMPLE I.
The naphthylamine hydrochloride obtained by treating 143 kilos of -naphthyl-
amine with 400 kilos of commercial hydrochloric acid is dissolved in 10,000
litres of water, the solution is heated to from 70° to 75° C. and there is added,
without continuing to heat, a solution of 150 kilos of commercial formaldehyde
of 40 per cent. strength and 600 kilos of sodium bisulphite solution of specific
gravity 38° Beaumé. The whole is allowed to cool and is filtered the residue
being washed on the filter. The yellowish precipitate thus obtained is entirely
soluble in alkalies; it cannot be diazotised but becomes slightly coloured on the
addition of some drops of sodium nitrite.
It is capable of combining with diazo bodies.
EXAMPLE II.
The benzidine hydrochloride obtained by treating 184 kilos of benzidine with
600 litres of commercial hydrochloric acid of specific gravity 21° Beaumé, is.
dissolved in 10,000 litres of water, the solution is heated to from 70° to 75° C.
and without continuing to heat there is added a solution of 150 kilos of commer-
cial formaldehyde of 40 per cent. strength and 600 kilos of sodium bisulphite
solution of specific gravity 38° Beaumé; the whole is allowed to cool and is fil-
tered. The precipitate thus obtained is in the form of a creamy bluish white
mass, insoluble in water but soluble in alkalies; from the alkaline solutions the
original compound is precipitated by the addition of acid.

page_text: If the operation has been properly conducted the filtered liquor will rarely
contain unchanged benzidine and will very rarely yield a precipitate on the addi-
tion of sulphate or of sulphuric acid or of caustic soda.
In the Example II. an equi-molecular proportion of tolidine, ethoxy- or meth-
oxy-benzidine, dianisidine, para- or meta-phenylenediamine, azoxyaniline or
azoxytoluidine or the like may be substituted for the benzidine.
The new compounds derived from the diamines are clearly differentiated from
the parent diamines by the following characteristics:
Insolubility in acids such as hydrochloric acid and the like.
:.
Solubility in alkalies and precipitation from these solutions by acids, and
Capacity for diazotisation exacly one half of that of the parent diamines.
When to these characteristics is added this one, namely that the diazo-
derivatives of these new compounds combine with amines or phenols not sulpho-
nated, yielding azo-colouring matters which are very soluble in water, while the
parent diamines yield colouring matters which are insoluble or very little soluble,
it may be concluded that the new compounds are either sulphonated or sulphi-
nated.
These compounds like those obtained as in Example I are capable of uniting
with diazo combinations.
EXAMPLE III.
375 kilos of the compound obtained in Example II., that is to say by the
action of sodium bisulphite and formaldehyde on benzidine, are dissolved in a
little dilute soda lye and there are added 710 grams of sodium nitrite, a slight
excess of commercial hydrochloric acid, about 25 kilos, and ice to keep the tem-
perature in the vicinity of from 5° to 10° C.; after an hour the mixture is poured
into an alkaline solution of about 26 kilos of the sodium naphthol disulphonate
(R salt). The mixture is allowed to stand for some hours, during which time it
is stirred, and the colouring matter is precipitated.
There is thus obtained a violet-blue colouring matter.
With Piria's naphthionic acid there is obtained an orange colouring matter,
with Schaeffer's salt a garnet-coloured colouring matter; with R salt a blue
violet coloured colouring matter; with G salt a yellowish garnet coloured colour-
ing matter with amidonaphthol G a black colouring matter; with H salt a blue
colouring matter with chromotrope acid a violet colouring matter; with salicylic
acid a green yellow colouring matter.
In Example III tolidine, dianisidine, methoxy, or ethoxy, benzidine, para- or
meta-phenylenediamine, azoxyaniline or azoxytoluidine from the nitrotoluidine
which melts at 107° C. may be substituted for the benzidine.
With azoxytoluidine, the R salt vields a very bright poppy-red colour.
On wool, with azoxytoluidine, N W salt also gives a poppy red colour,
Schaeffer's salt a very red orange and G salt
fine orange.
All the colouring matters are very soluble in water and generally difficult to
precipitate by common salt; they dye wool in an acid bath very well and cotton
in a neutral or alkaline bath a little less well than do the colouring matters
derived from the unchanged diamines.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is: -
1. The herein described process for transforming, by means of formaldehyde
and sodium bisulphite or sulphurous acid, primary aromatic amines into com-
pounds which (except that from aniline) are insoluble in water, but soluble in
alkalies and are not capable of diazotisation.
2. The herein described process for transforming by means of formaldehyde
and sodium bisulphite or sulphurous acid, the primary aromatic diamines, capable
of being bidiazotised, into new sulphonated or sulphinated compounds soluble in
alkalies, insoluble in acids, and capable of being monodiazotised.

page_text: 3. The herein described process for coupling the monoazo, diazo or monodiazo
derivatives obtained by the action of nitrous acid on the new compounds with
phenols, naphthols, amido phenols and naphthols, and primary, secondary, or
tertiary amines, as well as their sulpho and carboxyl derivatives and those ob-
tained by the treatments referred to in Claims 1 and 2.
4. The new compounds manufactured as set forth in Claims 1 and 2.
5. The new colouring matters manufactured as set forth in Claim 3.
Dated this 20th day of January 1899
ABEL & IMRAY.
Agents for the Applicant.