Abstract
Reaction of cyclic α, β-unsaturated β-amino ketones with thiocyanogen was investigated. 3-Amino-5, 5- dimethy1-2-cyclohexen-1-one (1c) reacted with thiocyanogen in 1, 2-dichloroethane at 20°C to give 2-amino-5, 5-dimethyl-7-oxo-4, 5, 6, 7-tetrahydrobenzothiazole (3c) in 41% yield. The reaction of 3-substituted amino-2-cyclohexen-1-one (1a, b) and 3-substituted amino-5, 5-dimethyl-2-cyclohexen-1-one (1d, e) (substituent R2 : Me and Ph) with thiocyanogen at -5-20°C gave 3-methyl- or 3-phenyl-2-imino-7-oxo-4, 5, 6, 7-tetrahydro-benzothiazoline (4a, b) and 3-methyl- or 3-phenyl-5, 5-dimethyl-2-imino-7-oxo-4, 5, 6, 7-tetrahydrobenzothiazoline (4d, e) in 25-75% yield.
