Functionalization of Ethyl 6-Amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate: Facile Synthesis of a New Series of Pyrano[2,3-d]pyrimidine Derivatives.

Herein, synthesis of a new series of pyrano[2,3-d]pyrimidine scaffolds is presented. Ethyl 6-amino-4-(4-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate has been reacted with formamide, formic acid, urea, thiourea, semicarbazide, and thiosemicarbazide to give six new pyrano[2,3-d]pyrimidine derivatives in moderate to high yields (48–78%). Acylation and intramolecular cyclization of pyran with carbon disulfide, ethyl cyanoacetate, acetic anhydride, or chloroacetyl chloride has resulted in formation of the corresponding desired bicyclic pyrimidine derivatives. The chloromethyl derivative was subjected to nucleophilic substitution by its reaction with morpholine, piperidine or aniline resulting in the corresponding 2-substituted pyrimidine derivatives in good yields. [ABSTRACT FROM AUTHOR]