ChemInform Abstract: Ring Cleavage of Isoxazoles with Heterocyclic Amines. Synthesis of Fused Pyrimidines

The reaction between 2-substituted ethyl 2,5-dihydro-5-oxoisoxazole-4-carboxylates (2a,b) and heterocyclic amines 1, 4, and 6, having the amino group in position 2 with respect to the nuclear nitrogen afforded fused pyrimidines 3, 5, and 7.