113968-15-3Relevant articles and documents
POLARISED KETENE DITHIOACETALS. PART 50. REACTIONS OF α-AROYL-α-BROMOKETENE DITHIOACETALS WITH HYDRAZINE HYDRATE: FORMATION OF REARRANGED PYRAZOLES
Singh, Gurdeep,IIa, Hiriyakkanavar,Junjappa, Hiriyakkanavar
, p. 1945 - 1950 (2007/10/02)
The reactions of α-aroyl-α-bromoketene dithioacetals (2a-c) with hydrazine hydrate yields unexpected pyrazoles, i.e. 3(5)-aryl-5(3)-4-bis(alkylthio)pyrazoles (9) in varying yields.The corresponding S-ethyl-α-bromoketene dithioacetals (2d) gave only the bis(ethylthio)pyrazole (7d) and 4-amino-4(3)-ethylthiopyrazole (9d) under similar conditions.The reactions of cyclic α-bromoketene dithioacetals (2e-g) with hydrazine hydrate on the other hand afforded only the dithiinopyrazole derivatives (7e-g) in high yields.The probable mechanisms for the formation of the pyrazoles (7)-(9) have been suggested.