反应详情

Starting from (R)-2-methyl-propane-2-sulfinic acid [1-(5-bromo-2-fluoro-phenyl)-2,2-difluoro-eth-(E)-ylidene]-amide (intermediate A2.3) and ethyl 2-bromo-2-fluoroacetate, a mixture (1 major component) of the 2 diastereoisomers (2R,3R)-3-(5-bromo-2-fluoro-phenyl)-2,4,4-trifluoro-3-((R)-2-methyl-propane-2-sulfinylamino)-butyric acid ethyl ester and (2S,3R)-3-(5-bromo-2-fluoro-phenyl)-2,4,4-trifluoro-3-((R)-2-methyl-propane-2-sulfinylamino)-butyric acid ethyl ester was obtained as a light yellow viscous oil after chromatography on silica gel (Telos Flash Silica) using a gradient of heptane/ethyl acetate=100:0 to 60:30 as the eluent. MS (ISP): m/z=462.2 [M+H]+and 464.2 [M+2+H]+.