Synthesis of Novel 2-amino-6-oxo-3-(piperidinyla-midino)-4-aryl-6,7-dihydro-pyrano[2,3-d]-5,7-thiazol Derivatives by Domino Reaction under Microwave Irradiation

Seven novel 2-amino-6-oxo-3-(piperidinylamidino)-4-aryl-6,7-dihydro-pyrano[2,3-d]-5,7-thiazol derivatives, which are different with the products of 2-amino-3-cyano-6-oxo-4-aryl-6,7-dihydro-pyrano[2,3-d]-5,7-thiazol derivatives in the conventional heating conditions, were synthesized by using arylidenemalononitrile, 2,4-thiazolidinedione and piperidine in one-pot via microwave irradiation techniques. The reaction condition is mild and we get these new compounds high-efficiently in a very short reaction times, which provides an elegant methodology for the synthesis of highly functionalized pyrano[3,2-d]-5,7-thiazole derivatives. At the end, the reaction mechanism was discussed. The structures of these compounds were characterized by 1 H NMR, IR, MS and elemental analysis.