Eine einfache Synthese von 5H-Benzopyranopyrimidin-Derivaten mit Oxo-, Thioxo- und/oder Imino-Funktionen in 4- und 5-Stellung

Article abstract of DOI:10.1055/s-1986-31504

The reaction of 4-dicyanomethylene- or 4--2-(2-hydroxyphenyl)-4H-1,3-benzoxazine with ammonium acetate, hydrogen sulfide, or aqueous acid represents a useful method for the preparation of 4,5-(imino, thioxo, or oxo)-disubstituted 2-(2-hydroxyphenyl)-3,4-dihydro-5H-<1>benzopyrano<4,3-d>pyrimidines.