Production of a Novel Pyrazolon.
Year: 1890

page_text: Date of Application, 5th Nov., 1890
Complete Specification Left, 6th Aug., 1891-Accepted, 12th Sept.. 1891
TROVISIONAL SPECIFICATION.
[Communicated from abroad by THE FARBWERKE VORMALS MEISTER LUCIUS
AND BRUNING, of Hoechst am Maine, in the Empire of Germany.]
Production of a Novel Pyrazolon.
1, OLIVER IMRAY of No. 28 Southampton Buildings, Chancery Lane, in the
County of London, Fellow of the Institute of Patent Agents, do hereby declare
the nature of this invention to be as follows:-
Doctor Knorr has set forth, that pyrazol derivatives are formed in the action of
phenyl-hydrazine upon non-saturated ketones.
The same author has obtained in analogous reaction by the action of an acid of
the acrylic acid series (the cinnamic acid) upon phenyl-hydrazine a pyrazolon-
derivative (Ber. d. D. ch. Ges. vol. 20 p. 1107).
When for the cinnamic acid is substituted a fatty acid such as crotonic acid, this
acid also forms with phenylhydrazine a pyrazolon.
Whether there is formed in the first stage a hyrazide of the crotonic acid, as
Doctor Knorr apparently believes to be the case for the corresponding cinnamic
derivative, or whether as in the action of ammonia upon crotonic acid (Engel
comptes rendus v. 106 p. 1677, Ber. d. D. ch. Ges. vol. 21c p. 523) forming
beta-amido crotonic acid, so in the action of phenylhydrazine upon crotonic
acid there is in the first stage formed the body
my foreign correspondents leave an open question.
The production of the novel pyrazolon is carried out in the following way.
50 parts of crotonic acid and 63 parts of phenylhydrazine are heated on an oil
bath to from 130 to 140° C. and finally from 140° to 150° C. (temperature of the
melt) until the elimination of water, very active at the beginning, completely
The yellow red melt is left somewhat to cool and then mixed with half its
volume of methylalcohol. After standing 12 hours, the yellow colored hard crystals
of the pyrazolon become separated from the solution.
ccases.
When twice recrystallized from methylalcohol, the compound assumes a pure
white colour having a melting point from 84 to 85° C. In hot water the body
dissolves sparingly and crystallises from it on cooling down in the form of well shaped
prisms having a glassy lustre. With oxidising agents such as ferric chloride it
shows the pyrazolon reaction, that is to say, blue coloured flocculce which in
chloroform dissolve with intense blue color.
Dated this 8th day of November 1890.
COMPLETE SPECIFICATION.
Production of a Novel Pyrazolon.
I, OLIVER IMRAY of 28 Southampton Buildings, Chancery Lane, in the
County of London, Fellow of the Institute of Patent Agents, 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 :-
Doctor Knorr has set forth that pyrazol derivatives are formed in the action of
D

page_text: phenylhydrazine upon non-saturated ketones. The same author has obtained in
analogous reaction by the action of an acid of the acrylic acid series (the cinnamic
acid) upon phenylhydrazine a pyrazolon-derivative (Ber. d. D. ch. Ges. vol. 20,
p. 1107).
When for the cinnamic acid is substituted a fatty acid such as crotonic acid, this
acid also forms with phenylhydrazine a pyrazolon.
Whether there is formed in the first stage a hydrazide of the crotonic acid,
as Doctor Knorr apparently believes to be the case for the corresponding cin-
namic derivative, or whether as in the action of ammonia upon crotonic acid
(Engel comptes rendus v. 106, p. 1677, Ber. d. D. ch. Ges. v. 216, p. 523) forming
beta-amido crotonic acid, so in the action of phenylhydrazine upon crotonic
acid there is in the first stage formed the body
my foreign correspondents leave an open question.
The production of the novel pyrazolin is carried out in the following way :-
50 parts of crotonic acid and 63 parts of phenyl-hydrazine are heated on an oil
bath to from 130 to 140° C. and finally from 140° to 150° C. (temperature of the
melt) until the elimination of water, very active at the beginning, completely
Cerses. The yellow red melt is left somewhat to cool and then mixed with half its
volume of methyl alcohol. After standing 12 hours the yellow colored hard crystals
of the pyrazolon becomes separated from the solution.
When twice recrystallised from methyl alcohol the compound assumes a pure
white colour; having a melting point from 84° to 85° C. In hot water the body
dissolves sparingly and crystallises from it on cooling down in the form of well
shaped prisms, having a glassy lustre. With oxidising agents such as ferric
chloride it shows the pyrazolon-reaction, that is to say, blue colored flocculce, which
in chloroform dissolve with intense blue color.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The herein described process for producing a pyrazolon having the character-
istic properties hereinbefore set forth, by the action of phenyl-hydrazine upon
crotonic acid.
2. As a new product the pyrazolon above referred to.
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