Novel 2-amino-3-pyrazol-5-yl-pyridines from the reaction of 5-chloro-1,8-naphthyridines with hydrazine hydrate and their cyclisation to pyrazolo[1,5-c]pyrido[3,2-e]pyrimidines, a new ring system
Abstract
5-Chloro-1,8-naphthyridines react with hydrazine hydrate to give 2-amino-3-pyrazol-5-yl-pyridines, which can form pyrazolo [1,5-c]pyrido[3,2-e]pyrimidines with triethyl ortho-esters.