Trifluoroacetic acid → HCID 54535466, compound

Participants

Reaction Steps

Nα-t-Butoxycarbonyl-L-tryptophyl-O-benzyl-L-seryl-O-benzyl-L-tyrosyl-D-leucine methyl ester (Example 17), 1 g., 1.16 mmol, is reacted according to the appropriate part of Example 1 with 20 ml. of trifluoroacetic acid, neutralized with triethylamine and coupled with 150 mg., 1.17 mmol, of cyclohexane carboxylic acid using 180 mg., 1.17 mmol, of 1-hydroxybenzotriazole and 240 mg., 1.17 mmol, of dicyclohexylcarbodiimide. The solution is evaporated and the residue triturated with ether. The product is precipitated from isopropanol on cooling as a cream solid; 1 g.; m.p. 158°-160° C.

Provenance & Evidence