Dimethyl Sulfoxide → 3-[(3,4-Dichloro-phenyl)-(2-oxo-ethyl)-amino]-propionic Acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 1.91 ml (21.77 mmol) of oxalyl chloride in 64 ml CH2Cl2 at −50 to −60° C. was added a solution of 3.22 ml (45.42 mmol) dimethylsulfoxide in 12 ml of CH2Cl2 within 20 min. The solution was stirred for 5 min, then a solution of 6.33 g (18.93 mmol) of 3-[(3,4-dichloro-phenyl)-(2-hydroxy-ethyl)-amino]-propionic acid tert-butyl ester in 43 ml CH2Cl2 was added within 20 min. The mixture was stirred for 15 min and 13.17 ml (94.63 mmol) of triethylamine were added within 20 min. The suspension was stirred for 3 h and slowly warmed to 0° C. The reaction was neutralized with cold aq. 10% KH2PO4 solution (adjusted with solid KH2PO4 to pH 4-5) and extracted with EtOAc (3×). The organic phases were washed with aq. 10% KH2PO4, solution sat. aq. NaHCO3 solution, aq. 10% NaCl solution, dried over Na2SO4 evaporated to yield 6.26 g (99.6%) of the title compound as orange oil. MS: 332.0 (MH+, 2Cl).

Provenance & Evidence