IMINIUM CARBONIC-ACID DERIVATIVE SALTS .11. SYNTHESIS OF N,S-CONTAINING HETEROBICYCLES FROM N-PROTECTED 2-METHYLTHIO-1,3-THIAZINIUM AND 2-METHYLTHIOTHIAZOLIUM SALTS .3. REACTION OF N-PROTECTED 2-METHYLTHIO-1,3-THIAZINIUM AND 2-METHYLTHIOTHIAZOLIUM SALTS WITH 3-AMINO-2-CYANO-3-ARYLACRYLONITRILES
W. Hanefeld et al., IMINIUM CARBONIC-ACID DERIVATIVE SALTS .11. SYNTHESIS OF N,S-CONTAINING HETEROBICYCLES FROM N-PROTECTED 2-METHYLTHIO-1,3-THIAZINIUM AND 2-METHYLTHIOTHIAZOLIUM SALTS .3. REACTION OF N-PROTECTED 2-METHYLTHIO-1,3-THIAZINIUM AND 2-METHYLTHIOTHIAZOLIUM SALTS WITH 3-AMINO-2-CYANO-3-ARYLACRYLONITRILES, Journal of heterocyclic chemistry, 33(6), 1996, pp. 1903-1907
N-Boc-protected 2-methylthio-1,3-thiazinium 1 and 2-methylthiothiazoli
um iodides 2, 3 obtained from the corresponding 3,4,5,6-tetrahydro-2H-
1,3-thiazine-2-thiones and thiazolidine-2-thiones by the action of met
hyl iodide were reacted with 3-amino-2-cyano-3-arylacrylonitriles form
ing the cyclic isothioureas 5-7. The protection group was removed with
trifluoroacetic acid whereupon the desired cyclisation to 3,4-dihydro
-2H,6H-pyrimido[2,1-b][1,3]thiazines 8a-c, 8a'-c' and thiazolo[3,2-b]p
yrimidines 9a,b, 9a',b', 10a,b took place.