Synthesis and potential biological activity of some novel 3-[(N-substituted indol-3-yl)methyleneamino]-6-amino-4-aryl-pyrano(2,3-c)pyrazole-5-carbonitriles and 3,6-diamino-4-(N-substituted indol-3-yl)pyrano(2,3-c)pyrazole-5-carbonitriles

Abstract

Synthesis and potential biological activity of some novel 3-[( N -substituted indol-3-yl)methyleneamino]-6-amino-4-aryl-pyrano(2,3- c )pyrazole-5-carbonitriles and 3,6-diamino-4-( N -substituted indol-3-yl)pyrano(2,3- c )pyrazole-5-carbonitriles Starting from N -substituted indole-3-carboxaldehydes ( 1a-g ) a series of new 3-[( N -substituted indol-3-yl)methyleneamino]-6-amino-4-aryl-pyrano(2,3- c )pyrazole-5-carbonitriles ( 3a-g and 4a-g ) have been synthesized via the acid catalyzed condensation reaction of 1a-g with 3-amino-5-pyrazolone, followed by the reaction with arylidene malononitriles. A series of new 3,6-diamino-4-( N -substituted indol-3-yl)pyrano(2,3- c )pyrazole-5-carbonitriles ( 7a-g ) have been prepared either via the base catalyzed condensation reaction of 1a-g with 3-amino-5-pyrazolone to give 6a-g , followed by the reaction with malononitrile or by the reaction of N -substituted-3-indolylidene malononitriles ( 5a-g ) with 3-amino-5-pyrazolone. According to the obtained results, the newly synthesized compounds possess significant anti-inflammatory, analgesic and anticonvulsant activities. The anticonvulsant potency of certain tested compounds was more pronounced than both anti-inflammatory and analgesic activities. Moreover, most of the newly synthesized compounds possess potential antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa.