4-Methylmorpholine → HCID 131713594, compound

Participants

Reaction Steps

A solution of 11.7 grams of tert. butyloxycarbonyl-L-alanine in 500 ml. of acetonitrile is cooled to -20° and 6.8 ml. of N-methylmorpholine is added, followed by 8.1 ml. of isobutyl chloroformate. The reaction mixture is allowed to stir for 5 minutes at -20° and a solution of 15.4 grams of 4-(S)-(phenylmethyl)-L-proline, phenylmethyl ester, hydrochloride and 6.8 ml. of N-methylmorpholine in 500 ml. of chloroform is added. The reaction mixture is allowed to warm slowly to room temperature, with stirring. After 18 hours the solvent is evaporated under reduced pressure. The oily residue is partitioned between ethyl acetate and water. The ethyl acetate layer is then washed with 0.2 N aqueous hydrochloric acid, water and with saturated aqueous sodium bicarbonate solution. The ethyl acetate layer is dried over anhydrous magnesium sulfate and concentrated under reduced pressure to yield the desired 1-[N-(1,1-dimethylethoxycarboxy)-L-alanyl]-4-(S)-(phenylmethyl)-L-proline, phenylmethyl ester.

Provenance & Evidence