4-Methylmorpholine → N-[(1S)-1-(Ethoxycarbonyl)-3-phenylpropyl]-L-alanyl-L-proline phenylmethyl ester

Participants

Reaction Steps

To an ice-cooled solution of L-proline benzylester hydrochloride (0.58 g) and crude N-(1-(s)-Ethoxycarbonyl-3-Phenylpropyl)-L-Alanine Hydrochloride (0.73 g) in DMF/CH2Cl2 (1:1, 20 ml) is added N-methylmorpholine (0.53 g), followed by 1-hydroxybenzotriazole (0.38 g). After 15 min of stirring, a cold solution of dicyclohexylcarbodiimide (0.65 g) in dry methylenedichloride (6 ml) is added and the mixture stirred at 0°-5° C. for 1 hour, then allowed to cool at room temperature overnight. The mixture is filtered and the filtrate after washing with aqueous NaHCO3 concentrated in vacuo to dryness to give 1.35 g of yellow viscous oil [TLC (Silica gel; CHCl3 /acetone=9:1); Rf=0.4]. The crude product is used for next reaction without further purification.

Provenance & Evidence