4-Toluenesulfonyl chloride → 4-{4-[(2S)-2-tert-Butoxycarbonyl-2-(toluene-4-sulfonylamino)-ethyl]-phenoxy}-butyric acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

411 mg of 4-[4-((2S)-2-amino-2-tert-butoxycarbonyl-ethyl)-phenoxy]-butyric acid ethyl ester were dissolved in 10 ml of anhydrous DMF and cooled to 0° C. 191 mg of 4-toluenesulfonyl chloride and 0.34 ml of diisopropylethylamine were added and the reaction mixture was stirred at room temperature overnight. The reaction mixture was filtered and the solvents removed in vacuo. The residue was chromatographed on silica gel eluting with n-heptane/ethyl acetate (1/1). Yield 295 mg. MS (ES+): m/e=506.2 (M+H)+; 450.2.

Provenance & Evidence