Synthetic routes to thiazolo[3,2-a]pyrimidin-7-ones via 1-allyl-2-thiouracil
Abstract
The reaction of 1-allyl-2-thiouracil (4) with l2-AgOAc in refluxing AcOH proceeds to 2-methyl-7H-thiazolo[3,2-a]pyrimidin-7-one (5)via a series of intramolecular transformations. The intermediates, 2-iodomethyl-2,3-dihydro-7H-thiazolo[3,2-a]pyrimidin-7-one hydroiodide (6) and 2,3-dihydro-2-methylene-7H-thiazolo[3,2-a]pyrimidin-7-one (10), were investigated. The syntheses are also described of 1-allyl-5-bromo-2-thiouracil (9), 2-acetoxymethyl-(11) and the hydrobromide of 2-bromomethyl-(14) 7H-thiazolo[3,2-a]pyrimidin-7-ones.