The reactions of semicarbazide and thiosemicarbazide with ferrocenyl-substituted α,β-enones

Semicarbazide (hydrochloride) and thiosemicarbazide react with α,β-unsaturated ketones of the ferrocene series in excess of tBuOK to give 1-carbamoyl- and 1-thiocarbamoyl(ferrocenyl)-4,5-dihydropyrazoles. The condensation with thiosemicarbazide is accompanied by the fragmentation of the starting α,β-enones resulting in ferrocenecarbaldehyde or acetylferrocene thiosemicarbazones.