Manufacture of Nitroalphylpyruvic Acids."
Year: 1897

page_text: Date of Application, 30th Jan., 1897.
Complete Specification Left, 29th Oct., 1897-Accepted, 4th Dec., 1897
PROVISIONAL SPECIFICATION.
"Manufacture of Nitroalphylpyruvic Acids."
I, OLIVER IMRAY, of No 28 Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, do hereby declare the nature of this
invention (as communicated to me from abroad by The Farbwerke vormals Meister
Lucius and Brünning of Hoechst a/Main in the Empire of Germany, Chemical
Manufacturers) to be asfollows:-
It has been found, that nitro derivatives of toluene and its homologues may be
condensed with esters of oxalic acid in presence of an alcoholic solution of sodium
ethylate or methylate to form nitroalphylpyruvic acids.
The following is an example of the process.
To an alcoholic solution of sodium ethylate obtained by dissolving 46 parts by
weight of sodium in 20 times its weight of absolute alcohol are added 137 parts by
weight of nitrotoluene and 146 parts by weight of oxalic ester, while being cooled ;
the solution is left to itself at ordinary temperature or is slightly heated on the water
bath.
At a higher temperature the reaction is accelerated, but then there is formation of
by-products, the quantity of which increases with the temperature; heating beyond
50° C. is therefore not advisable.
To separate the new acid, hydrochloric acid may be added to link the sodium,
whereupon the alcohol is distilled off and the unchaned nitrotoluene is expelled by
steam.
The remaining solution is filtered and the dissolved o-nitrophenylpyruvic acid is
obtained by concentratingor extracting the solu-ion with ether. On recrystallisation
from benzene, the acid forms brilliant yellowish laminae having a melting point of
about 121° C.
In the same way the corresponding nitroalphylpyruvic acids may be obtained for
instance from p-nitrotoluene and nitro p-xylene.
“Manufacture of Nitroalphylpyruvic Acids.'
İ, OLIVER IMRAY formerly of No. 28 Southampton Buildings, Chancery Lane, in
the County of London, but now of Birkbeck Bank Chambers, Southampton Buildings,
Chancery Lane, in the County of London, Chartered Patent Agent, do hereby declare
the nature of this invention (as communicated to me from abroad by The Farbwerke
vorinals Meister Lucius and Brüning of Hoechst a/ Main, in the Empire of Germany

page_text: Chemical Manufacturers) and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
It has been found, that nitro derivatives of toluene and its homologues may be
condensed with esters of oxalic acid in presence of an alcoholic solution of sodium
ethylate or methylate to form nitroalphyl pyruvic acids.
The following is an example of the process :-
To an alcoholic solution of sodium ethylate obtained by dissolving 46 parts by
weight of sodium in 20 times its weight of absolute alcohol are added 137 parts by
weight of o-nitrotoluene and 146 parts by weight of oxalic ester, while being cooled;
the solution is left to itself at ordinary temperature or is slightly heated on the water
bath.
At a higher temperature the reaction is accelerated, but then there is formation of
by-products, the quantity of which increases with the temperature; heating
beyond 50° C. is therefore not advisable.
To separate the new acid, hydrochloric acid may be added to link the sodium,
whereupon the alcohol is distilled off and the unchanged nitrotoluene is expelled by
steam.
The remaining solution is filtered and the dissolved o-nitrophenylpyruvic acid is
obtained by concentrating or extracting the solution with ether. On recrystallisation
from benzene, the acid forms brilliant yellowish laminæ having a melting point of
about 121° C.
In the same way the corresponding nitroalphylpyruvic acids may be obtained for
instance from p-nitrotoluene p-nitro-in-alkyl oxytoluene and nitro-p-xylene.
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 manufacture of o- and p-nitrophenylpyruvic acids by condensing nitrated
toluenes or their higher homologues in o- or p- position with the esters of oxalic
acid, substantially as described.
2. The o- and p-nitrophenylpyruvic acids manufactured as above set forth.