A Convenient Synthesis of N1-Substituted 3,4-Dihydropyrimidin-2(1H)-ones by Cyclocondensation of (alpha)-Chlorobenzyl Isocyanates with Ethyl N-alkyl(aryl)-(beta)-aminocrotonates

A new convenient approach to the synthesis of N1-substituted 3,4-dihydropyrimidin-2(1H)-ones was developed using the regioselective cyclocondensation of (alpha)-chlorobenzyl isocyanates with ethyl N-alkyl(aryl)-(beta)-aminocrotonates. A number of N1-aryl and N1-alkyl substituted Biginelli compounds difficult to obtain by other methods were prepared with high yields.