Manufacture of New Basic Dyestuffs.
Year: 1899

page_text: Manufacture of New Basic Dyestuffs.
I, JOHN IMRAY, of Birkbeck Bank Chambers, Southampton Buildings, Chancery
Lane, in the County of London, Consulting Engineer and Chartered Patent
Agent, do hereby declare the nature of this invention (as communicated to me
from abroad by La Société L. Durand Huguenin & Ce, of Basle, Switzerland;
Manufacturers) to be as follows:-
By the action of phthalic anhydride or monoalkylated meta-amidophenols in
the presence of zinc chloride there are formed, besides symmetrical dialkylrhod-
amines, yellowish brown products soluble in alkalies, which can be purified
by dissolution in dilute ammonical alcohol and subsequent precipitation by acids
and recrystallisation.
They are thus obtained in the form of yellow needles which are insoluble
in dilute acids, but dissolve in alcohol and in dilute alkalies. The alcoholic
ammoniacal solution fluoresces green.
My foreign correspondents have now found that these compounds can be
esterified and that when thus treated they yield dyestuffs, soluble in water,
which dye tannin-mordanted cotton yellow to brown tints.
EXAMPLE.
20 kilos of the crystals obtained from mono-ethylmeta-amido-phenol in the
manner above described are heated on the water bath for about 12 hours with
80 kilos of alcohol and 80 kilos. of sulphuric acid (monohydrate). The mixture
is poured into about 800 litres of water which is kept alkaline with caustic
soda. The residue is dissolved in alcohol, kept slightly acid with hydrochloric
acid, and the liquid is filtered. Water is added to the filtrate until this becomes
turbid and crystallisation is allowed to ensue. The dyestuff is purified by several
recrystallisations; it dyes tannin-mordanted cotton yellow tints.
Dated this 1st day of Anvil:1800
ABEL & IMRAY,
Agents for the Applicant.

page_text: Agent, do hereby declare the nature of this invention (as communicated to me
from abroad by La Société L. Durand Huguenin & C., of Basle, Switzerland,
Manufacturers) and in. what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:-
-
By the action of phthalic anhydride on mono-alkylated meta-amidophenols
in the presence of zinc chloride there are formed, besides the symmetrical
dialkylrhodamines, certain bye-products which are yellowish brown in colour
and soluble in alkalies. These can be purified by dissolving them in dilute
ammoniacal alcohol and subsequent, precipitation by acids and recrystallisation.
They are thus obtained in the form of yellow needles. This purification can
be effected by other suitable treatment with alkalies and acids. Thus the raw
bye-product can be treated with caustic soda or sodium carbonate solution in.
an open vessel or preferably under pressure and subsequently treated with alcohol
and hydrochloric acid until the resinous or pitchy admixtures are removed and
the desired yellow crystals remain behind as a paste. The purified bye-pro-
duct thus obtained is insoluble in dilute acid but dissolves in alcohol or dilute
alkalies. The alcoholic and ammoniacal solution possesses a green fluorescence.
The present invention of my foreign correspondents consists in manufacturing
new basic dyestuffs by esterifying the purified crystallised bye-product obtained
in the manner above described. The said dyestuffs are soluble in water, and
dye tannin-mordanted cotton giving yellow to brown tints. The esterification
can be effected by treatment with alcohol and a mineral acid or if desired the
new crystalline initial material can be esterified by treatment with halogen
alkyl.
The following examples will serve to illustrate the manner in which the inven-
tion can be carried into practical effect for manufacture of the new basic
dyestuffs.
EXAMPLE 1.
20 kilos of the crystals obtained from mono-ethyl-meta-amido-phenol in the
manner above described are heated in the water-bath for about twelve hours
with 80 kilos of alcohol and S0 kilos. of sulphuric acid (monohydrate). The
mixture is poured into about 800 litres of water which is kept alkaline with
caustic soda, and the temperature during this mixture is preferably regulated
so that it does not exceed 35° C. The residud is dissolved in alcohol, kept
slightly acid with hydrochloric acid and the liquid is filtered.
Water or pre-
ferably aqueous hydrochloric acid is added to the filtrate until this becomes
turbid and crystallisation is allowed to ensue. The dyestuff is purified by several
re-crystallisations; it dyes tannin-mordanted cotton yellow tints.
EXAMPLE 2.
About 30 parts of the yellow crystalline initial material, 6 parts of caustic
soda, 200 parts of alcohol, and 40 parts of ethyl chloride, are mixed and the
mixture is heated in an autoclave for about 8 hours at a temperature of 120° C.
The alcohol and any excess of ethyl chloride are distilled off and the residue is
ground with cold, very dilute caustic soda lye so as to free it from any unchanged
initial material that may be mixed with it.
The new basic dyestuff is insoluble in alkali and is collected by filtering,
washed with water, and dissolved in hot purified alcohol containing hydro-
chloric acid. On cooling, a portion of the colouring-matter separates. By the
addition of hydrochloric acid the precipitation is rendered more complete. If
necessary the dyestuff is purified by several recrystallisations.
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:-
R
The manufacture of new basic dyestuffs by esterifying the purified crystal-

page_text: line yellow bye-product obtained by the action of phthalic anhydride or mono-
alkylated meta-amido-phenols in presence of zinc chloride.
2. The new basic dyestuffs manufactured as above set forth.
Dated this 28th day of December 1899.
ABEL & IMRAY,
Agents for the Applicant.