Synthesis of novel 5,6,7-substituted 3-phenyl-6,7-dihydroisoxazolo[4,5-d]pyrimidines

In this work we present a convenient synthetic route to novel 5,6,7 -substituted 3-phenyl-6,7-dihydroisoxazolo[4,5-d]pyrimidines. The key synthetic step is based on the cyclization of 4-amino-3-phenylisoxazole-5-carboxamides and ethyl 4-[(ethoxymethylene)amino]-3-phenylisoxazole-5-carboxylates. The developed methodology can be easily adapted to high-throughput combinatorial format.