Triethylamine → HCID 70090354, compound

Participants

Reaction Steps

To a solution of N-benzyloxycarbonyl-L-valine (50.0 g) and N-cyclopentylglycine t-butyl ester (39.8 g) in dichloromethane (1.3 liter), stirred under nitrogen and cooled in an ice bath to 0°-5° C., was added triethylamine (44.5 g) then bis(2-oxo-3-oxazolidinyl)phosphinic chloride (56.0 g) at 0° C. The stirred mixture was allowed to warm to room temperature overnight before it was evaporated. After the residue was partitioned between water (1 liter) and ethyl acetate (1 liter), the ethyl acetate solution was washed (1N hydrochloric acid (twice), water, saturated sodium bicarbonate, brine), dried (MgSO4) and evaporated. The residue was purified by flash chromatography, eluting with ethyl acetate:dichloromethane (0:100, 5:95, 10:90 and 25:75, successively). A first, mixed fraction was rechromatographed and the product obtained combined with the product obtained from the first chromatography to afford the ester (73.4 g, 85%); TLC, Rf =0.30, ethyl acetate:dichloromethane (5:95); MS, m/e=433 (M+1), 377, 325, 269, 234, 286, 162, 144 91(base).

Provenance & Evidence