Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Facile decarbonylation of the 4-formyl group in 5-alkyl amino pyrazoles was seen when reacted with catalytic p-toluene sulfonic acid in methanol under microwave irradiation to provide parent 4-H pyrazoles in good yields. ... Facile decarbonylation of the 4-formyl group in 5-alkyl amino pyrazoles was ...