Lithium hydroxide, monohydrate → [4-(Cyclopropyl-methyl-amino)-5,6,7,8-tetrahydro-benzo[4,5]thieno[2,3-d]pyrimidin-2-yl]-methanol

To a solution of acetic acid 4-(cyclopropyl-methyl-amino)-5,6,7,8-tetrahydro-benzo[4,5]thieno[2,3-d]pyrimidin-2-ylmethyl ester (4 g, 0.012 mol) in THF (10 ml) and water (5 ml) was added lithium hydroxide monohydrate (1.48 g, 0.036 mol). The solution stirred at room temperature for 4 h. The volatiles were removed by distillation, and the residue was diluted with water, and extracted with ethyl acetate (3×25 ml). The combined organic layers were dried over anhydrous sodium sulphate, concentrated, and purified by chromatography on 60-120 silica gel using 25%-ethyl acetate in hexane to give the desired product [4-(cyclopropyl-methyl-amino)-5,6,7,8-tetrahydro-benzo[4,5]thieno[2,3-d]pyrimidin-2-yl]-methanol (2.5 g, 72%) as off-white solid. 1H NMR (400 MHz, CDCl3): δ 0.45-0.50 (m, 2H), 0.72-0.80 (m, 2H), 1.72-1.80 (m, 2H), 1.88-1.94 (m, 2H), 2.82-2.94 (m, 5H), 3.07 (s, 3H), 3.94 (t, 1H), 4.70 (d, 2H); LC-MS: [M+H]=290.0 m/z.