1963 年 83 巻 4 号 p. 373-377
Reaction of 2-ethoxymethyl-3-ethoxy-3-methoxypropionitrile (I), 2-methoxymethylene-3-ethoxypropionitrile (II), or 2-ethoxymethoxymethylacrylonitrile and o-nitrophenylhydrazine gives 1-(o-nitrophenyl)-3-pyrazoline-4-carbonitrile (VI), whose catalytic reduction over 2.5% palladium-carbon gives 1-(o-aminophenyl) compound (VII) and its diazotization affords 1H-benzo[e]pyrazolo[1, 2-a][1, 2, 3, 4]tetrazine-2-carbonitrile (VIII). On the other hand, treatment of VI with 35% palladium-carbon gives 1-(o-nitrophenyl)-4-pyrazolecarbonitrile (IX) and its catalytic reduction over 2.5% palladium-carbon results in amination to X whose diazotization gives 1-phenyl-4-pyrazolecarbonitrile (XI). By a similar reaction, ethyl 2-ethoxymethyl-3-ethoxy-3-methoxypropionate (IV) and ethyl 2-methoxymethylene-3-ethoxypropionate give ethyl 1-(o-nitrophenyl)-3-pyrazoline-4-carboxylate (XV), whose treatment with 35% palladium carbon affords the pyrazole compound (XVI). Catalytic reduction of XVI and diazotization give ethyl 1-phenyl-4-pyrazolecarboxylate (XVIII). Reaction of I, II, III, IV, and V with 2, 4-dinitrophenylhydrazine results in the formation of corresponding 1-(2, 4-dinitrophenyl)-3-pyrazoline-4-carbonitrile and ethyl 1-(2, 4-dinitrophenyl)-3-pyrazoline-4-carboxylate.