Ethyl ester of carboxy-phenyl-propyl alanyl proline

摘要

1-(N-(5)-1-carboxy 3-phenyl propyl) L-alanyl L-proline 1'-ethyl ester of formula (I) is made by (a) treating a cpd. (II) with L-alanyl 2-proline at ambient temp. for 1-2 h.; and (b) reducing the Schiff's base by addn. of trimethylamino borane at ambient temp. with agitation for 1-2 h.. A mixt. of R and S isomers in concn. of 2-8% is obtained. The concentrate is treated several times with ethyl acetate and dried with anhydrous Na2SO4, giving (I).