5-Chloro-2(1H)-pyrimidinone → 5-Chloro-1-(4-methylthiophenacyl)pyrimidin-2-one

A suspension of 5-chloropyrimidin-2-one (312 mg) and 2-bromo-4'-methylthioacetophenone (525 mg) in triethylamine (1 ml) and ethanol (20 ml) was stirred at ambient temperature for 2.25 hours. The resulting suspension was concentrated at reduced pressure then diluted with water (50 ml). The collected precipitate was crystallised from acetone to give the title pyrimidinone (404 mg,); m.p. 192°-197°, λmaxEtOH 229 nm (ε 14450), 312 nm (ε 21470), λinf 239.5 nm (ε 9930).