
TY  - JOUR
A1  - Singh, H 
A1  - Singh, S 
T1  - Synthesis of heterocyclics via enamines. I. Formation of 1,4-Dihydropyrimidine-2-thiols and 2-Amino-1,3-thiazines in reactions of ethyl &#946;-aminocrotonates with &#946;-keto isothiocyanates: role of solvents
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1973
VL  - 26
IS  - 11
SP  - 2453
EP  - 2457
KW  - 
UR  - https://doi.org/10.1071/CH9732453 
N2  - Ethyl &#946;-aminocrotonate (1) on condensation with the &#946;-keto isothiocyanate (2; R = Me) in hexane, benzene, or toluene formed the 1,4-dihydropyrimidine-2-thiol (3; R = Me) as the major product and the 2-amino-1,3-thiazine (4; R = Me) as the minor component. The use of ether, acetonitrile, butan-2-one, ethyl acetate, chloroform as solvents reversed the product ratio. In the reaction with (2; R = Et), the yields of (3 and 4; R = Et) formed were similarly affected by change of solvent. 
ER  -

