Synthesis of 1,3,5-trisubstituted pyrazole-4-carboxylates through 1,3-dipolar cycloaddition of nitrilimines with allenoates

A strategy for the 1,3-dipolar cycloaddition of nitrilimines to delta-allenoates has been developed to provide various 1,3,5-trisubstituted pyrazole-4-carboxylates and pyrazole-4-carboxamide derivatives, which have excellent anticancer effects. This protocol exhibits characteristics of good yield, mild reaction condition, facile operation process and post-processing steps. (C) 2022 Elsevier Ltd. All rights reserved.