4-Methylmorpholine → Boc-prolylproline benzyl ester

Participants

Reaction Steps

To a suspension of L-proline benzyl ester hydrochloride (3.37 g) in dichloromethane (60 ml) were added N-methylmorpholine (1.54 ml), N-(t-butoxycarbonyl)-L-proline (3.00 g), HOBt (2.08 g) and water-soluble carbodiimide hydrochloride (2.95 g) in order, followed by stirring for 1 hour. After stirring at room temperature for 17 hours, the reaction mixture was poured into ethyl acetate, washed with 1N hydrochloric acid, a saturated aqueous solution of sodium bicarbonate and saturated brine in order, dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by silica gel column chromatography (eluate; hexane-ethyl acetate) to give 5.00 g of the title compound.

Provenance & Evidence