Diisopropylamine → 6-bromo-2-[2-(2,6-difluoro-3,5-dimethoxyphenyl)ethyl]-5-(phenylsulfonyl)-5H-pyrrolo[2,3-b]pyrazine

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of N,N-diisopropylamine (0.150 mL, 1.07 mmol) in tetrahydrofuran (0.48 mL) at 78° C., n-butyllithium (2.5 M in hexanes, 0.428 mL, 1.07 mmol) was added dropwise. After a white precipitate formed, the mixture was warmed up to 0° C. for 10 minutes. The resulting solution was added to a stirred solution of 2-[2-(2,6-difluoro-3,5-dimethoxyphenyl)ethyl]-5-(phenylsulfonyl)-5H-pyrrolo[2,3-b]pyrazine (400 mg, 0.871 mmol) in tetrahydrofuran (3 mL) at 78° C. After 10 minutes, a solution of 1,2-dibromo-1,1,2,2-tetrachloroethane (0.283 g, 0.870 mmol) in tetrahydrofuran (2 mL) was added dropwise. After another 1 hour, the reaction mixture was quenched with saturated aq. NH4Cl, then extracted with methylene chloride. The combined organic layers were dried over MgSO4, then concentrated. The residue was purified on silica gel (eluting with 0 to 50% EtOAc in hexanes) to give the desired product (330 g, 70%). LCMS calculated for C22H19BrF2N3O4S (M+H)+: m/z=538.0. Found: 538.0.

Provenance & Evidence