4-Methylmorpholine → HCID 54262973, compound

Participants

Reaction Conditions

Reaction Steps

14.0 Parts N-t-butoxycarbonyl-L-tyrosylglycyl-L-alanine and 3.5 parts N-methylmorpholine are dissolved in 200 parts dimethylformamide and cooled to -15° C. Then, 5.2 parts isobutyl chloroformate is added dropwise over a 30 minute period while maintaining the temperature at -15° C. Then, a solution of 9.8 parts L-phenylalanyl-L-leucine benzyl ester in 50 parts dimethylformamide is slowly added at -15° C., and the mixture stirred at this temperature for 30 minutes. The cooling apparatus is removed and the mixture stirred at ambient temperatures for an additional two hours. The product is isolated by diluting the reaction mixture with 10 volumes water and extracting with ethyl acetate. The ethyl acetate extracts are combined, dried over anhydrous sodium sulfate and stripped to dryness under reduced pressure. Purification of the residue by low pressure column chromatography affords N-t-butoxycarbonyl-L-tyrosylglycyl-L-alanyl-L-phenylalanyl-L-leucine benzyl ester.

Provenance & Evidence