Synthesis of heterocycles via enamines-XIII1 1 H. Singh, S. Kumar, J. Chem. Soc., Perkin Trans 1, 1987, in press. Steric control on the mode of reactions of β-isothiocyanatoketones with amino-acids

Article abstract of DOI:10.1016/S0040-4020(01)86799-5

Glycine and anthranilic acid with 4-isothiocyanato-butan-2-one (1) gives 3-(3-oxobutyl)-4-oxoimidazolidine-2-thione (11) and 3-(3-oxobutyl)-2-thioxoquinazolin-4-one (15) whereas with 4-isothiocyanato-4-methylpentan-2-one (2), having a gem-dimethyl group at the carbon bearing isothiocyanate group, tetrahydro-7,7,8a-trimethyl-5-thioxo-6H-oxazolo[3,2-c] pyrimidine-2(3H)-one (14) and 2,3,4,4a-tetrahydro-3,3,4a-trimethyl-1-thioxo-1H,6H-pyrimido[1,6a][3,1]-benzoxazin-6-one (17) are formed.