Synthesis of functionaeized 1h-pyrazolo[4,3-e]-[1,2,4]triazines and their fused derivatives via ipso-substitution of methyesulfonyl croup with o-,n-,s- and c-nucleophiles

摘要

Ipso-substitution reaction of 3-methyl-5-methylsulfonyl-l-phenyl-1H-pyrazolo[4,3-e][ 1,2,4]triazine (4) with a range of C-,N-,O- and S-nueleophiles afforded the corresponding substitution products (5a-m) in high yields.The reaction of 5-hydrazino compound (5m) with carboxylic acids furnished lH-pyrazolo[4,3-e]-l,2,4-tria7olo[4,3-b][l,2,4]tria/ines (8a) and (8b).