ChemInform Abstract: Polarized Ketene Dithioacetals. Part 50. Reactions of α‐Aroyl‐α‐bromoketene Dithioacetals with Hydrazine Hydrate: Formation of Rearranged Pyrazoles.

Abstract Reaction of the dithioacetals (Ia)‐(Ic) according to A) yields the corresponding pyrazoles (II)‐(IV), whereas in the case of (Id) only type (II) and (IV) is formed.