SOME REACTIONS OF CHALCONE-4-SULFONYL CHLORIDE AND 4-METHOXYCHALCONE-3-SULFONYL CHLORIDE

Chalcone and 4-methoxychalcone react with chlorosulfonic acid to give chalcone-p-sulfonyl chloride and 4-methoxchalcone-3-sulfonyl chloride respectively. The sulfonyl chlorides were converted into 13 sulfonyl derivatives by reaction with nucleophiles. With hydrazine and phenylhydrazine the chalconesulfonyl chlorides were cyclised to the corresponding hydrazinopyrazolines. In contrast, with N,N-dimethyl-hydrazine only the dimethylsulfonohydmides were obtained, and no attack on the carbonyl group was observed. Possible reasons for this difference in behaviour are discussed, together with spectroscopic evidence for the structures proposed.