Tetrahydrofuran → HCID 67235388, compound

Participants

Reaction Conditions

Reaction Steps

A solution of (R)-ethyl 3-(5-bromo-2-fluorophenyl)-3-((R)-1,1-dimethylethylsulfinamido)-2,2-difluorobutanoate (intermediate A3.1) (10.5 g, 23.6 mmol) in anhydrous tetrahydrofuran (150 ml) was cooled to −78° C. and was treated dropwise with a solution of methylmagnesium bromide (3.2 M in 2-methyl-tetrahydrofuran; 59.1 ml, 189 mmol). The cooling bath was removed, and the mixture was stirred at 23° C. for 18 hours. For the workup, the reaction mixture was poured cautiously into a saturated solution of ammonium chloride and extracted with ethyl acetate. The organic layer was washed with brine and dried over sodium sulphate. Removal of the solvent in vacuum left the (R)-N-((R)-2-(5-bromo-2-fluorophenyl)-3,3-difluoro-4-hydroxy-4-methylpentan-2-yl)-2-methylpropane-2-sulfinamide (10.565 g, 23.6 mmol, 99.7% yield) as a yellow gum, which was used in the next step without further purification. MS (ISP): m/z=430.1 [(M+H)+] and 432.1 [(M+2+H)+].

Provenance & Evidence