Synthesis of some new thiazolo, pyrano and pyrimidinone derivatives of expected biological activities

Reaction of 6-hydroxy-2-thio-2,3-dihydro 1-H-pyrimidin-4-one(1) with phenacylbromide, monochloro acetic acid, ketones, 1,2-dibromo ethane and 1,3-dichloropropane to yield thiazolo [3,2-a] pyrimidin-5-one derivatives (2-7a,b). Condensation of (1) with chalcones and hydrazonoyl chloride gave compounds (8a,b), (9a,b) and (10a,b) respectively. On the other hand condensation of 8a with chlorocetic acid gave compound (11), which react with benzaldehyde to give 12, the allowed compound 12 react with NH2OH.HCl to give compound 13. Condensation of (8a) with ketones, phenacyl bromide, 1,2-dibromoethane, 1,3-dichloropropane and hydrazonoyl chloride to gave pyrano pyrimidinone derivatives (14-19), also compound (8a) reacted with acetic acid with added drops of conc. H2SO4 gives bis compound (20).