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

Abstract 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.