4-Methylmorpholine → 2-[(N-benzyloxycarbonyl-trans-4-hydroxy-L-prolyl)-L-valyl]amino-6-methylbenzoic acid

Participants

Reaction Steps

Isobutyl chloroformate (0.23 ml) was added to a tetrahydrofuran solution (3.5 ml) containing N-benzyloxycarbonyl-trans-4-hydroxy-L-proline (463 mg) and N-methylmorpholine (0.19 ml) at -15° C., and the mixture was stirred for 0.5 hour. An N,N-dimethylformamide solution (2.5 ml) containing 6-methyl-2-(L-valylamino)benzoic acid (291 mg) and N-methylmorpholine (0.15 ml) was added dropwise to the above mixture at -15° C., and the resultant mixture was stirred at -15° C. for 0.5 hour and then at room temperature for two hours. The reaction mixture was treated by the same procedures as in item (c) of Example 1 to obtain 2-[(N-benzyloxycarbonyl-trans-4-hydroxy-L-prolyl)-L-valyl]amino-6-methylbenzoic acid (570 mg).

Provenance & Evidence