1958 年 78 巻 4 号 p. 334-337
Reaction of compounds (A) related to 2-acetylpropionitrile (III), an intermediate in the synthesis of sulfisoxazole, with semicarbazide hydrochloride and hydrazine sulfate was examined. Compounds tested were the ester (I), acid amide (II), nitrile (III), imido ester (IV), and amidine (V) of 2-acetylpropionic acid and following facts were revealed.
In reaction of semicarbazide hydrochloride, (I), (II), and (III) formed corresponding semicarbazones (VI), (VII), and (VIII), in the presence of sodium acetate. These semicarbazones underwent cyclization by the action of acid or alkali to form 1-car-bamoylpyrazole derivatives (C). In the case of (IV) and (V), however, (B) is not obtained and (C) is formed directly.
(C) derived from (I) or (II) liberates the carbamoyl group by heat to form a pyrazole derivative (E) but (E) is not obtained from (C) derived from (III), (IV), and (V).
(I) and (II) react with hydrazine sulfate to form (E) via the intermediate (D), but (III), (IV), and (V) do not afford (D) and (E).
Acetylsulfanilyl derivative (XV) of (V), however, undergo these reactions, same as (I) and (II), such as (A)→(B)→(C)→(D)→(E) and (A)→(E).