1-(p-Chlorobenzenesulfonyloxy)-6-chloro-1,2,3-benzotriazole → N-[(1,1-Dimethylethoxy)carbonyl]-D-alanine 2,5-dioxo-1-pyrrolidinyl ester

Participants

Reaction Steps

To a mixture of Boc-L-Ala-D-Glu(OH)OMe (1)(1.33 g), L-Lys(ε-Boc)-GlyOEt (2)(2.02 g) and 1-(4-chlorobenzenesulfonyloxy)-6-chlorobenzotriazole (1.38 g) in methylene chloride (50 ml) was added N-methylmorphorine (0.808 g) at 0° C. and the mixture was stirred for 30 minutes at the same temperature and for 2 days at room temperature. The reaction mixture was washed successively with 5% aqueous sodium bicarbonate, water, 5% hydrochloride acid and water, dried over magnesium sulfate and evaporated to give a crystalline mass, which was washed with ether to give Boc-L-Ala-γ-D-Glu(α-OMe)-L-Lys(ε-Boc)-GlyOEt (3)(1.96 g).

Provenance & Evidence