Synthesis of 1-Substituted and 1-Unsubstituted 4-Sulfonamid0-1H-pyrazol-5(2H)-ones

All articles of this category 4-Sulfonamido-1 H -pyrazol-5(2 H )-ones bearing different substituent groups on the nitrogen atom in position 1 were easily obtained by reaction of conjugated azoalkenes with sulfonamides under mild conditions. 1-Unsubstituted title compounds were smoothly obtained by solvolytic cleavage of the substituent groups in methanol under reflux. alkoxycarbonylazoalkenes - aminocarbonylazoalkenes - sulfonamides - 1-substituted 4-sulfonamido-1 H -pyrazol-5(2 H )-ones - 1-unsubstituted 4-sulfonamido-1 H -pyrazol-5(2 H )-ones