4-Methoxybenzenesulfonyl chloride → ethyl (1S,3R,4R)-2-[(4-methoxyphenyl)sulfonyl]-2-azabicyclo[2.2.1]heptane-3-carboxylate

To a solution of ethyl (1S, 3R, 4R)-2-azabicyclo[2.2.1]heptane-3-carboxylate (807 mg, 4.77 mmol) in chloroform (8 ml) were added triethylamine (0.67 ml, 4.77 mmol) and 4-methoxybenzenesulfonyl chloride (1.08 g, 5.25 mmol) while being cooled with ice. After a reaction at room temperature for 4 hours, the reaction mixture was washed with 1N hydrochloric acid, saturated sodium bicarbonate water and saturated brine successively, and dried over magnesium sulfate. The solvent was evaporated and the residue was recrystallized (hexane/ethyl acetate), to give ethyl (1S, 3R, 4R)-2-[(4-methoxyphenyl) sulfonyl]-2-azabicyclo[2.2.1]heptane-3-carboxylate (0.965 g, 60%).