4-Methylmorpholine → Acetylalanylalanylprolyl-2-azaalanyl-l-lactic acid ethyl ester

Participants

Reaction Steps

To a stirred solution of acetylalanylalanylproline (0.66 mole) and N-methylmorpholine (0.66 mole) in dry tetrahydrofuran (25 ml) at -20° to -25° is added isobutylchloroformate (0.66 mmole). After 10 minutes a solution of 2-azaalanyl-l-lactic acid ethyl ester (0.66 mmole, example 3, step B) in tetrahydrofuran (2 ml) is added dropwise and the mixture is allowed to warm to room temperature over a period of 1 hour and stirred for a further 3 hours. The precipitate is removed by filtration, and the filtrate is concentrated to dryness. Chromatography of the residue on a silica gel (30 gm) and elution with 8% methanol in chloroform yields acetylalanylalanylprolyl-2-azaalanyl-l-lactic acid ethyl ester.

Provenance & Evidence