Synthesis and electron impact of mass spectra of some heterocycles containing coumarin moiety

Reaction of 6-bromo-3-ethoxycarbonylcoumarin (1) with resorcinol, thiourea and 2-aminophenol yielded the corresponding 11-bromo-3-hydroxy chromeno[3,2-c] chromen-6,7-dione (2), 6-bromo-3-methoxycarbonyl-coumarin (3),9-bromo-5-oxo-5H-4-hydroxybenzopyrano [3,4-d]-pyrimidin-2-thione (4) and 6-bromo-3-(2hydroxyphenylaminocarbonyl)coumarin (9), respectively. Treatment of compound 2 with ethyl chloroacetaite and acetic anhydride afforded the corresponding 11-bromo-3-ethoxycarbonylmethoxy (or acetyloxy)-chromeno [3,2-c] chromen-6,7-diones (5 and 6).6-Bromo-3-(benzoxazol-2-yl)coumarin (10) was obtained by cyclization of 9 with phosphorus oxychloride. The electron impact mass spectra of both of the above compounds have also been recorded and their fragmentation pattern is discussed.