Studies on Syntheses of Pyrazolone and Pyrazole Derivatives. III. Syntheses of 3-Substituted 5-Methoxy-1-phenylpyrazole Derivatives

Abstract

For studies on biological activity, syntheses of 3-substituted 5-methoxy-1-phenylpyrazoles were attempted. N-Substituted 5-methoxy-1-phenylpyrazol-3-ylacetamides (IIa-m) were obtained from (Ia-c). 3-Aminomethyl-5-methoxy-1-phenylpyrazole (V) was synthesized from Ia or IIm by the Schmidt reaction or Curtius reaction. N-Acylmethylamine derivatives (VIa-c, VIIIa-h) and Melubrin-type XIa were obtained from V, but the attempt to prepare N-alkylamine derivatives of V was unsuccesful. 3-Chloromethyl-5-methoxy-1-phenylpyrazole (IX) was synthesized from V, and N-alkylamine derivatives (Xa-m) and sulpyrin type (XIb) were obtained from IX.