Various acyclic α -halo-β -amino- and α -thiocyanato-β -amino α, β -unsaturated ketones were prepared and their structures were established. The reaction of 4-amino- or 4-monosubstituted amino-3-Penten-2-one [1], 3-amino- or 3-menosubstituted amino-1-phenyl-2-buten-X-one [2]and 3-amino- or 3-monosubstituted amino-1, 3-diphenyl-2-propen-1-one [3] with N-chloro- or N-bromo-suecinimides under nitrogen atmesphere at O-50 C gave 4-amino- or 4-monesubstituted amino-3-halo-3-penten-2-one (Cl [4 a - c] and Br [7 a - c]), 3-amino- or 3-monosubstituted amino-2-chlero-1-phenyl-2-buten-1-one[5 a - c] and 3-amino- or 3-monosubstitued amino-1, 3diphenyl-2-halo-2-propen-1-one (Cl[6 a - c] and Br[8 a - c]), respectively. The substituents on nitrogen are a: H, b: Me and c: Ph. The reaction of [1 a - c] and [2 a] with thiecyanogen at -15-O C gave 4-amino- or 4-monosubstituted amine-3-thiocyanato-3-penten-2-one [9 a - c] and 3-amino-1-phenyl-2-thiodyanato-2-buten-1-one [10 a].
From the IR and NMR spectral data, it was confirmed that an ec-hydrogen atom, of the enamino ketones was substituted by halogen or thiocyanaeo group, and these products were inferred to exist in the intramolecular hydrogen bonded enamino ketone form. The effect of the α -sabstituent on the hydrogen bonded chelate ring was also discussed.