Diethyl Ether → N-p-methoxybenzyloxycarbonyl-D-serine benzyl ester

Participants

Reaction Steps

N-p-Methoxybenzyloxycarbonyl-D-serine (5.39 mg, 2.00 sm:ol; prepared as a colourless solid of m.p. 96°-97° C. in 60% yield by the dissolved in methanol and treated with a solution of potassium carbonate (138 mg, 1.00 mmol) in water (2 ml). The mixture is evaporated by dryness, N,N-dimethyl-forimide (DMF) is added and re-evaporated (2×2 ml), and the solid residue is then dissolved in dry warm DMF, benzyl bromide (248 μl, 2.1 mmol) is added and the solution is warmed in a dry closed flask at 50° C. for 1 hour. The resulting mixture is portioned between ether (10 ml) and water (10 ml) and the aqueous layer is extracted with ether (2×10 ml). The combined ether extracts are washed with saturated sodium bicarbonate (5 ml) and saturated brine (5 ml), dried and evaporated to dryness. The residue is purified on a column of silica gel using 1:1 v/v ethyl acetate:petroleum ether as eluant to yield to title compound as a homogenous oil (590 mg, 82%) which crystallises on standing to give a colourless solid of m.p. 67°-68° C. (from diethyl ether); [α]D20 --6.3° (c 4.0, CHCl3).

Provenance & Evidence