A MANUFACTURE OF OXYPYRAZOLS OR SUBSTANCES FORMED BY CONDENSING HYDRAZINES WITH THE ETHERS OF CARBOKETONIC ACIDS
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I, CHARLES DENTON ABEL of N° 28 Southampton Buildings Chancery Lane
in the County of Middlesex, Consulting Engineer and Patent Agent do hereby
declare the nature of the said Invention for "A MANUFACTURE OF OXYPYRAZOLS
OR SUBSTANCES FORMED BY CONDENSING HYDRAZINES WITH THE ETHERS OF
CARBOKETONIC ACIDS" to be as follows:-
This Invention consists in the preparation of oxypyrazols. What I call
oxypyrazols are substances formed by condensing bydrazines with the ethers of
carboketonic acids of the general formula R. CO. CHR. CO, C₂ Hε, the
condensation proceeding with formation of water and alcohol as shewn in the
following example.
According to a general reaction discovered by E. Fischer (see Berichte der
Deutschen chemischen Gesellschaft, Vol. XVI. p. 5.) acetylacetic ether unites with
phenylhydrazine under elimination of water to form the simple product of
condensation expressed by the formula:
C, H, N, H. C-
CO, C, H.
CH
This product in the shape of a yellow oil is obtained on mixing the above
components. It has been found by my foreign correspondents that when this oil
is heated a more complex condensation takes place, alcohol being eliminated and
methylphenyloxypyrazol is formed in the shape of a solid substance having the
composition Co H₁0 N, O. The reaction is expressed in the following equation:

page_text: acetylacetic ether and phenylhydrazine are mixed together. The phenylhydrazine
acetylacetic ether thus obtained is heated to a temperature of 100 degrees centigrade
until a sample solidifies perfectly on cooling or on being immersed into ether. The
methylphenyloxypyrazol thus obtained is easily purified by recrystallization. It is
distinguished by the following properties:
When it is heated with the chlorides, bromides or iodides of alcohol-radicals,
such alcohol-radical enters into the molecule by substitution to form new compounds.
Methylphenyloxypyrazol may for example be methylated and dimethylphenyloxy-
pyrazol be obtained by treating the former with methyliodide.
The dimethylphenyloxypyrazol thus obtained crystallizes in lamina having
a pearly lustre and melting at 113 degrees centigrade.
When methylphenyloxypyrazol is heated with dehydrating agents, as for instance
with an excess of phenylhydrazine, an anhydride of methylphenyloxypyrazol is
produced having the formula C₂ H₁s N, O.
In the same way as phenylhydrazine, the hydrazines obtained. from toluidine,
xylidine and naphthylamine etc. etc. react upon the ethers of carboketonic acids of
the general formula R. CO. CHR". CO,. C, H, as for instance upon acetylacotic
ether, benzoylacetic ether, diacetylsuccinic ether and succinylosuccinic ether, the
products being substituted oxypyrazols.
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton. Buildings,
London, W.C.

page_text: I, CHARLES DENTON ABEL of N° 28 Southampton Buildings Chancery Lane
in the County of Middlesex, Consulting Engineer and Patent Agent do hereby
declare the nature of the said Invention for "A MANUFACTURE OF OXYPYRAZOLS
OR SUBSTANCES FORMED BY CONDENSING HYDRAZINES WITH THE ETHERS Of
CARBOKETONIO ACIDS" and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement thereof,
that is to say:-
This Invention consists in the preparation of oxypyrazols. What I call
oxypyrazols are substances formed by condensing hydrazines with the ethers of
carboketonic acids of the general formula R. CO. CHRº. CO, C, H, the
condensation proceeding with formation of water and alcohol as shewn in the
following example:
According to a general reaction discovered by E. Fischer (see Berichte der
Deutschen chemischen Gesellschaft, Vol. XVI. p. 5) acetylacetic ether unites with
phenylhydrazine under elimination of water to form the simple product of
condensation expressed by the formula:

page_text: ether, benzoylacetic ether, diacetylsuccinic ether and succinylosuccinic ether, the
products being substituted oxypyrazols.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed I declare that what
I claim is-
1. The manufacture of bodies called oxypyrazols, and hereinbefore exemplified,
from ethers of the carboketonic acids of the general formula R¹. CO. CHR, CO,
C, H₂, such as acetylacetic ether, and hydrazines, such as phenylhydrazine, by
heating a mixture of molecular quantities of the same for several hours.
2. The production of the alkylderivatives of the oxypyrazols by the action of
alkyliodides, alkylchlorides or alkylbromides upon the oxypyrazols..
3. The production of dioxypyrazyls :
a, by the action of hydrazines upon the oxypyrazols,
b, by the action of hydrazines upon the ethers of the carboketonic acids,
using an excess of hydrazines.