Friedländer condensation of 5??aminopyrazole??4??carbaldehydes with reactive α??methylene ketones: Synthesis of pyrazolo [3, 4??b] pyridines

…, RB Toche, C Reidlinger, W Stadlbauer

Index: Jachak, Madhukar N.; Avhale, Appasaheb B.; Tantak, Chanda D.; Toche, Raghunath B.; Reidlinger, Claudia; Stadlbauer, Wolfgang Journal of Heterocyclic Chemistry, 2005 , vol. 42, # 7 p. 1311 - 1319

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Citation Number: 36

Abstract

Abstract A series of 1, 3, 6-trisubstituted and 1, 3, 5, 6-tetrasubstituted pyrazolo [3, 4-b] pyridines 5 has been synthesized by Friedlander condensation of 5-arninopyrazole-4- carbaldehydes 3 with α-methylene ketones such as acetone (4a) or acetophenones 4b-f with potassium hydroxide as basic catalyst. Condensation of 5-aminopyrazole-4- carbaldehydes 3 and unsymmetric dialkylketones 6 yielded mixtures of isomeric pyra-zolo ...