Methanesulfonyl chloride → [2-(4,4-Dimethylcyclohexyl)-5-methyl[1,3]thiazolo[5,4-d]pyrimidin-7-yl]methyl methanesulfonate

To a mixture of [2-(4,4-dimethylcyclohexyl)-5-methyl[1,3]thiazolo[5,4-d]pyrimidin-7-yl]methanol (6.42 g) and EtOAc (65 mL) were added dropwise TEA (4.5 mL) and MsCl (2.1 mL) under ice-cooling, followed by stirring at 0° C. for 1 hour. The reaction mixture was filtered and then to the liquid was added saturated aqueous sodium bicarbonate, followed by extraction with EtOAc. The organic layer was dried over MgSO4 and then concentrated under reduced pressure to obtain [2-(4,4-dimethylcyclohexyl)-5-methyl[1,3]thiazolo[5,4-d]pyrimidin-7-yl]methyl methanesulfonate (9.3 g).