Pyridine → (R)-4-(5-bromo-2-fluoro-phenyl)-3-(2,4-dimethoxy-benzyl)-4-methyl-[1,2,3]oxathiazolidine 2-oxide

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Reaction Conditions

Reaction Steps

To a solution of (R)-2-(5-bromo-2-fluorophenyl)-2-(2,4-dimethoxybenzylamino)propan-1-ol (14.1 g, 35.4 mmol, Eq: 1.00) and pyridine (14.0 g, 14.3 ml, 177 mmol, Eq: 5.0) in dichloromethane (258 ml) at 78° C. was dropwise added thionyl chloride (5.05 g, 3.1 ml, 42.5 mmol, Eq: 1.2), stirring was continued at 78° C. for 5 min, the cooling bath was removed and the mixture was slowly warmed up to 23° C. and stirring was continued for 20 min. Extracted with 5% citric acid and sat NaHCO3-sol., dried the organic layer over Na2SO4, filtered off and evaporated totally to give the (R)-4-(5-bromo-2-fluoro-phenyl)-3-(2,4-dimethoxy-benzyl)-4-methyl-[1,2,3]oxathiazolidine 2-oxide (15.7 g, 35.3 mmol, 99.8% yield) as a light yellow oil, which needed no further purification. MS (ISP): m/z=444.1 [M+H]+ and 446.0 [M+2+H]+.

Provenance & Evidence