Improvements in the manufacture
Year: 1895

page_text: Date of Application, 21st Jan., 139,5
Complete Specification Left, 21st Oct., 1895-Accepted, 23rd Nov., 1895
Improvements in the manufacture
1, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 following statement :-
I have found that the orange red dye stuff obtained from formaldehyde and
metaamidoparacresol (CH: NH2: OH = 1:2:4 see former Patent No. 123233),
when subjected to an alkylation is transformed into new dyestuffs of a redder shade
and of great brilliancy.
Similar dyestuffs are obtained by alkylating at an earlier stage of the process,
that is to say, 'by reacting with formaldehyde on monoalkylated metaamidoparacresol
aid transforming the thus obtained products of condensation into dyestuffs in an
analogous way to that described in former Patents Nos. 132178 and 1232303.
The new dyestuffs thus obtained are of basic nature and suitable for dyeing and
printing on cotton. The following is an exact description of the mauner in which

page_text: this invention may be carried out practically, the parts hereinafter given, being by
weight.
First Alkylation of the colouring matter described in former Patent 133238.
The alkylation is best effected by employing methylbromide (dissolved in
methylic alcohol) or ethylbromide. It is preferable to employ the free base of the
colouring matter instead of its salts. The alkylation takes place already at a
temperature of about 130° C., at higher temperatures, for instance at 170° C., redder
shades are obtained. The methylated products are in general of more reddish shade
than the ethylated ones.
As an example, 2 parts of the colouring base are heated in a closed vessel with
25 parts of spirit and 2 parts of ethylbromide during 3 hours at 130-140° C.,
After cooling the mass is diluted with 200 parts of water, the spirit is distilled
over, and after cooling the colouring matter is precipitated from the filtered liquid
by common salt.
:
Second: Colouring matter derived from monoalkylated metaamidoparacresol.
The best results are obtained by employing monoethylamidocresol, for which reason
this compound is hereafter especially referred to. The best method to obtain the
condensation product with formaldehyde is the following:
Dissolve 15 parts of pure monoethylmetaamidoparacresol in 300 parts of water
and 13 parts of caustic soda lye of 30%, add to the solution 3.7 parts of a solution
of formaldehyde of 40% and after standing some time heat to the boiling point.
When the smell of formaldehyde has disappeared, add a little quantity of acetic
acid in order to precipitate any impurities, filter and precipitate from the filtered
and somewhat cooled solution the diethyldiamidodioxyditolylmethan by means of
acetic acid:
: The product thus obtained is a colourless precipitate dissolving in dilute
mineralic acids or caustic soda lye. The melting point, when crystallized out of
spirit, has been found to be 169° C. .
In order to transform this condensation product into the corresponding colouring
matter, one part. is poured into 3 parts of concentrated sulphuric acid and the mass
is heated on the water bath, until the whole is dissolved. Dehydration is effected
after some hours and a yellowish red melt is obtained, dissolving in water with a
red colour and greenish yellow fluorescence. One part of the melt is then poured
into two parts of water, 2 parts of saltwater and 1.3 parts of ferric chloride
solution of 114 specific gravity are added and oxidation is completed at
about 90° C., the colouring matter separating in a crystalline state. It is filtered
off, well washed with saltwater and pressed.
.
It can be purified by dissolving in about 50 parts of water, filtering the solution,
and precipitating the nitrate of the colouring matter by a solution of nitrate
of soda.
Instead of ferric chloride, other oxidizing agents may be employed without
however having any advantage over the former.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the saine is to be performed, as communicated to me by
my foreign correspondents, I. declare that what I claim is :-
1
1. The production of dialkyldiamidodioxyditolylmethan and especially of
diethyldiamidodioxyditolylmethan by the herein before described process, which
consists in combining monoalkylated metaamidoparacresol (CH, : NHR : OH
1:2:4) with formaldehyde, substantially as described.
=
2. Diethyldiamidodioxyditolylmethan produced substantially as described.
3. The production of colouring matter by the herein described process which
consists in heating dialkyldiamidodioxyditolylinethan and especially diethyl-
diamidodioxyditolylmethan, with concentrated sulphuric acid and treating"
leucobodies thus formed with oxidizing agents.
'
4. The production of colouring matters by alkylating the orange red colouring

page_text: matter derived from formaldehyde and metaamidoparacresol (CH¸: NH, : OH =
1:2:4).
5. The new colouring matters produced according to Claims 3 and 4.
Dated this 21st day of October 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.