反应详情

To a mixture of 4-bromo-1-chloro-2-fluorobenzene (11.7 g, 56.0 mmol) and magnesium turnings (2.1 g, 84 mmol) in THF (150 mL) at RT was added a few drops of 1,2-dibromoethane (1.1 g, 5.6 mmol). The mixture was stirred at RT for 1.5 h. After cooling to −78° C., (R,E)-2-methyl-N-((1-methyl-1H-pyrazol-4-yl)methylene)propane-2-sulfinamide (4.00 g, 18.7 mmol) was added and stirred at −78° C. for 6 h. The reaction was quenched with aq. NH4Cl solution and extracted with EtOAc. The combined organic layers were dried (MgSO4), filtered, and concentrated. The crude product was purified by SiO2 chromatography eluting with DCM/MeOH (150:1) to afford the 2.9 g (45%) of (R)—N—((S)-(4-chloro-3-fluorophenyl)(1-methyl-1H-pyrazol-4-yl)methyl)-2-methylpropane-2-sulfinamide (48). LCMS (ESI) m/z: 344.1 [M+H]+.

1. temperatureAfter cooling to −78° C.
2. stirringstirred at −78° C. for 6 h
3. customThe reaction was quenched with aq. NH4Cl solution
4. extractionextracted with EtOAc
5. dry with materialThe combined organic layers were dried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated
8. customThe crude product was purified by SiO2 chromatography
9. washeluting with DCM/MeOH (150:1)