Thiazolo quinazoline-5-thiones

Methyl-4-oxoquinazolinyl-2-thiolacetic acid (378), obtained by the reaction of 6-methyl-4-oxoquinazoline-2-thione (377) and chloroacetic acid, upon treatment with acetic anhydride-pyridine, yields a cyclized product confirmed by the molecular ion peak [M] at m/z 232 and for which structure 7-methyl-2//-thiazolo[3,2-n]quinazolin-l,5-dione (379) was assigned on the basis of IR and H-NMR data in preference to possible... 

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