Manufacture of Ethoxyphenylmethylpyrazolone and of Para-ethoxy- 1 phenyl-2-3-dimethyl-5 pyrazolone.
Year: 1892

page_text: Date of Application, 10th Feb., 1892
Complete Specification Left, 9th Nov., 1892-Accepted, 17th Dec., 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by DIE FARBWERKE VORMALS MEISTER LUCIUS
AND BRUNING, of Hoechst */ Main, Germany, Chemical Manufacturers.]
Manufacture of Ethoxyphenylmethylpyrazolone and of Para-ethoxy-
1 phenyl-2-3-dimethyl-5 pyrazolone.
I, OLIVER IMRAY of No. 28 Southampton Buildings, in the County of London,
Chartered Patent Agent, do hereby declare the nature of this invention to be as
follows:-
When diazotised para-phenetidine is heated in hydro-chloric solution with
stannous chloride there separates immediately the hydrochlorate of para-phenetyl-
hydrazin in the form of white needles and which contains some tin.
By treating the aqueous solution of the hydrochlorate of para-phenetylhydrazin
with alkalies there is separated the free base, crystallising from its ether solution in
the form of leaflets of the melting point 74° C.
When this base is admixed with acetylacetic ether there separates first water;
on being left standing for a longer time or on being heated, the formation of
ethoxyphenylmethylpyrazolone sets in while alcohol separates, according to the
equation:

page_text: With ferric chloride the para ethoxy 1 phenyl 2-3 dimethyl 5 pyrazolone
produces a red solution, with nitrous acid, a blue green liquid from which are
rapidly deposited crystals of the nitroso-body.
Dated this 10th day of February 1892.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
፡፡
Manufacture of Ethoxyphenylmethylpyrazolone and of Para-ethoxy-
1 phenyl-2-3-dimethyl-5 pyrazolone.
I, OLIVER IMRAY of No. 28 Southampton Buildings in the County of London,
Chartered Patent Agent, 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:-
. When diazotised para-phenetidine is treated in hydro-chloric solution with
stannous chloride there separates immediately the hydrochlorate of para-phenetyl-
hydrazin in the form of white needles and which contains some tin.
By treating the aqueous solution of the hydrochlorate of para-phenetylhydrazin
with alkalies there is separated the free basec crystallizing from its ether solution
in the form of leaflets of the melting point 74° C.
When this base is admixed with acetylacetic ether there separates first water;
on being left standing for a longer time or on being heated, the formation of
ethoxyphenylmethylpyrazolone sets in while alcohol separates, according to the
equation:
as follows:
15-2 parts by weight of para-phenetyl-hydrazin are dissolved in 13 parts by
weight of acetylacetic ether.
The mass is separated from the water, emulsioned at the beginning, then left to
rest for a longer space of time.
Having cooled down, the mass is finely powdered treated with ether and well
washed with ether. By recrystallisation from alcohol there is obtained the
ethoxy-phenyl-methyl-pyrazolone in the form of compact crystals of the melting
point 147° C. The body dissolves in acids and alkalies; on being treated with
ferric chloride a blue oxydation product results.
By treatment with alkylising agents such as iodide, bromide, chloride of methyl,
methylsulphates etc. etc. the para ethoxy-phenylmethylpyrazolone is converted into
para ethoxy-1-phenyl 2-3 dimethyl-5 pyrazolone.
This conversion is carried out for example in the following manner :
10 parts by weight of para-ethoxy phenyl methyl pyrazolone
6.5
32
"
"
"
iodide of methyl
25
"
"
"
"
wood spirit (pyroligneous spirit)
are heated in an autoclave to about 100° C. for 12 hours, after having cooled down
the alcohol is expelled, the liquid is discolored by means of sulphurous acid, and
by means of soda-lye the para-ethoxy-1-phenyl-2-3 dimethyl-5 pyrazolone is
precipitated in the form of a thick oil. The precipitated oil is taken up with
benzene, and the benzene solution is dried by means of carbonate of potassium.
On. concentrating the benzene-solution there is obtained the para ethoxy-1-phenyl
2-3-dimethyl-5 pyrazolove in the form of compact crystals of the melting

page_text: point 89° C., easily soluble in water, alcohol and benzene, but soluble with difficulty
in ether.
With ferric chloride the para ethoxy-1-phenyl 2-3-dimethyl-5 pyrazolone
produces a red solution; with nitrous acid, a blue green liquid from which are
rapidly deposited crystals of the nitroso-body.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The production of ethoxy phenylmethylpyrazolone by treating para phenetyl
hydrazine with acetyl-acetic ether.
2. The production of para ethoxy-1-phenyl 2-3-dimethyl-5 pyrazolone by
methylising the para ethoxy phenyl-methylpyrazolone.
3. The para ethoxyphenylmethylpyrazolone manufactured in the manner referred
to in Claim 1.
4. The para ethoxy-1-phenyl-2-3-dimethyl-5 pyrazolone manufactured in the
manner referred to in Claim 2.
Dated this 6th day of November 1892.
ABEL & IMRAY,
Agents for the Applicant..