Triethylamine → 2-cyclopentyl-7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidin-4-yl trifluoromethanesulfonate

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Reaction Steps

To a suspension of 2-cyclopentyl-7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidin-4-ol (2.9 g, 12.3 mmol) in methylene chloride (100 mL) at 0° C. was added N,N-dimethylaminopyridine (0.020 g, cat.), triethylamine (3.5 mL, 24.6 mmol) and trifluoromethanesulfonic acid (2.3 mL, 13.5 mmol). The suspension was warmed to rt and stirred for 3 h. The mixture was cooled to 0° C. and the reaction was quenched with a saturated solution of NaHCO3. The organic layer was washed a saturated solution of NaHCO3 and brine. The organic layers were dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated. The residue was purified by column chromatography (silica, hexanes/ethyl acetate) to afford the title compound (3.40 g, 75%) as, a yellow solid. MW=368.40. 1H NMR (CDCl3, 500 MHz) δ 3.28-3.20 (m, 1H), 3.10-3.05 (m, 1H), 2.98 (t, J=6.5 Hz, 2H), 2.31-2.24 (m, 2H), 2.09-1.99 (m, 2H), 1.89-1.76 (m, 4H), 1.70-1.62 (m, 2H); APCI MS m/z 369 [M+H]+.

Provenance & Evidence