Recyclization of the products of amidine addition to the substituted 5-amino-4-cyano-1,3-oxazole into new derivatives of 5,6-Diaminopyrimidin-4-one

The products of addition of amidines to accessible 5-arylamino-4-cyano-1,3-oxazoles at heating in acetic acid undergo recyclization and afford new derivatives of 6-amino-5-acylaminopyrimidin-4-one, whose structure was reliably established using X-ray diffraction studies.