Sulfuric Acid → (S)-2-tert-Butoxycarbonylamino-3-(2-nitro-benzenesulfonylamino)-propionic acid

Participants

Reaction Conditions

Reaction Steps

(S)-2-tert-Butoxycarbonylamino-3-amino-propionic acid (14.9 g, 73.2 mmol) was dissolved in a mixture of THF (45 mL) and 3 N aq. NaOH (45 mL). The reaction mixture was cooled to −10° C. and nosyl chloride (17.9 g, 80.5 mmol) was added as a THF solution (75 mL) drop wise over 30 min. The reaction mixture was stirred at −10° C. for 45 min followed by stirring at ambient temperature for 30 min. The reaction mixture was diluted with water (150 mL), acidified with 2% aqueous H2SO4 (to pH ˜2) and diluted with additional water (450 mL). The product was extracted with EtOAc (600 mL total) and washed with water (3×400 mL) and brine (100 mL). The organic layer was separated, dried over Na2SO4, filtered and condensed in vacuo to afford compound A (20.0 g, 70% yield) as a cream solid. LC-MS [M+H-Boc] 290.3 (C14H19N3O8S+H, calc: 390.4). Purity >95% (UV/254 nm). Compound A was used without further purification.

Provenance & Evidence