11 g (25 mmol) of methyl 3-benzyloxy-3-phenyl-2-hydroxybutyrate (comp. 1.1) are dissolved in 50 ml of dichloromethane, 3 g (30 mmol) of triethylamine are added and, while stirring, 3.2 g (28 mmol) of methanesulfonyl chloride are added dropwise. The mixture is stirred at room temperature for 2 hours, washed with water, dried over magnesium sulfate and concentrated under reduced pressure. The residue is taken up in DMF and added dropwise to a suspension of 12.9 g (75 mmol) of 4,6-dimethoxypyrimidine-2-thiol and 8.4 g (100 nmol) of sodium DMF at 0° C. After stirring at room temperature for 2 hours and at 60° C. for a further 2 hours, the mixture is poured into 1 1 of ice-water, and the precipitate is filtered off with suction. Drying results in 3.2 g of a white powder.
