4-Methylmorpholine → N-[3-(ethoxycarbonyl)-2-(2-methylpropyl)propanoyl]-O-methyl-L-tyrosine N-methylamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(ethoxycarbonyl)-2-(2-methylpropyl)propanoic acid (17.4 g., 0.087 mol.), N-methylmorpholine (28.7 mls., 0.26 mol.) and dimethylformamide (0.25 ml.) was dissolved in dry dichloromethane (200 mls.) and the resulting mixture was cooled to 0° C. To the reaction mixture was added a solution of oxalyl chloride (7.6 mls., 0.087 mol.) in dry dichloromethane (50 mls.). The mixture was heated under reflux for 10 minutes and then cooled to -70° C. To the reaction mixture was added O-methyl-L-tyrosine N-methylamide (20.0 g, 0.096 mol.) in dry dichloromethane (100 mls.) over a period of 30 minutes. The resulting mixture was allowed to warm to room temperature and stirred for 2.5 days. The mixture was filtered and the filtrate washed with saturated sodium bicarbonate solution (2×200 mls.), dilute citric acid (2×150 mls.) and then dried over anhydrous sodium sulfate. The solvent was then removed by evaporation in vacuo to yield N-[3-(ethoxycarbonyl)-2-(2-methylpropyl)propanoyl]-O-methyl-L-tyrosine N-methylamide, as a mixture of isomers (20.7 g.), in the form of a solid.

Provenance & Evidence