Synthesis of pyrano[2,3-d]pyridine, pyrazolo[3,4-b]pyridine derivatives by microwave irradiation and study of their insecticidal activity

Sunita A. Chaudhari (Patil), S

Abstract

5-Amino pyrazole 4[1] was transformed to pyrazolo pyridine derivatives 7 by microwave irradiation with diethyl malonate. Alternatively it was synthesized by two step process through open chain derivative 6 then it was transformed to 7 by refluxing in biphenyl ether. N- Alkylation reaction on 7 was studied by ethyl bromo acetate and also by microwave irradiation. The pyran ring was annulated on 7 by condensing it with by benzilidine malononitrile. All synthesized compounds were characterized by spectral and analytical methods. It was noted that synthesis and alkylation of 7 was performed in microwave and it is faster than conventional method. The biological activity of compounds 7, 9 and 11 were studied.