1,2-Dibromoethane → Ethyl 4-bromo-2-methyl-2-(methylsulfonyl)butanoate

Participants

Reaction Steps

Sodium hydride (60% dispersion in mineral oil, 2.33 g, 58.3 mmol) was washed with hexane (2×10 mL) in a 100 mL two neck round bottom flask under nitrogen then suspended in DMF (30 mL). The suspension was treated dropwise with ethyl 2-(methylsulfonyl)propanoate (10.0 g, 55.49 mmol) in DMF (10 mL). The mixture was stirred 30 min at RT, cooled to 0° C., and treated dropwise with 1,2-dibromoethane (5.17 mL, 58.8). The mixture was allowed to warm to room temperature while stirring overnight. The mixture was quenched with saturated ammonium chloride (100 mL) and the mixture was extracted with diethyl ether (4×50 mL). Combined organics were washed with 50% saturated sodium chloride (4×50 mL), dried (MgSO4), filtered and the filtrate concentrated in vacuo. Crude material was chromatographed over silica gel (350 g, 230-400 mesh) eluting with 10-20% EtOAc/hexane to afford the title compound as a pale yellow oil (7.9 g, 50%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.33 (t, J=7.05 Hz, 3H) 1.64 (s, 3H) 2.49-2.59 (m, 1H) 2.78 (ddd, J=13.89, 10.16, 6.64 Hz, 1H) 3.05 (s, 3H) 3.33-3.41 (m, 1H) 3.46-3.54 (m, 1H) 4.22-4.37 (m, 2H).

Provenance & Evidence