Synthesis of Newly Substituted Pyrazoles and Substituted Pyrazolo[3,4‐b]Pyridines Based on 5‐Amino‐3‐Methyl‐1‐Phenylpyrazole

The reaction of the aminopyrazole 1 with benzenesulfonyl chloride, arenediazonium salt, chloroacetyl chloride, ethoxy methyleneamlononitrile and with ethyl 2‐cyano‐3‐ethoxyacrylate gave the substituted 3‐methyl‐1‐phenylpyrazole 2–5a,b . Compound 5b was cyclized to 6 and to 7 by treating it with AlCl₃ and with POCl₃, respectively. Compound 6 converted to 7 by boiling it in POCl₃/PCl₅. Compound 10b was produced through reaction of 9 with acetophenone. Reaction of 1 with benzylidinemalononitrile afforded 11 . New methods for preparation of 15 and 16 are described. The reaction of 8 with malononitrile, thiosemicarbazide, phenyl hydrazine and acetophenone afforded compounds 18–21 . The reaction of 21 with malononitrile gave 22 . Compounds 23–26 were produced upon reaction of 10a with malononitrile, phenyl hydrazine, thiosemicarbazide, semicarbazide and with benzaldehyde, respectively.