Methyl iodide → 1-[(1,1-Dimethylethyl)(dimethyl)silyl]-3,3-dimethyl-2-pyrrolidinone

Participants

Reaction Conditions

Reaction Steps

In an oven-dried 1000 ml 3-neck flask fitted with septa and thermometer was charged with diisopropylamine (0.177 mol, 17.9 g) and 300 ml THF. The solution was cooled to 0° C. and n-Butyl lithium (0.193 mol, 77.1 ml of a 2.5M solution in hexanes) was added with stirring over 5 min. After 30 min, the reaction was cooled to −78° C. and a solution of 1-[(1,1-dimethylethyl)(dimethyl)silyl]-3-methyl-2-pyrrolidinone (0.161 mol, 34.3 g) in 80 ml THF was added dropwise keeping reaction temperature below −60° C. Once complete, the reaction was warmed to 20° C. After 1 hr, the reaction was cooled to −78° C. and a solution of Iodomethane (0.177 mol, 25.1 g) in 10 ml of THF was added dropwise over 10 min. The reaction was warmed to 20° C. and stirred for 16 hr, after which time 300 ml saturated NH4Cl was added. The aqueous phase was extracted with ethylacetate (2×150 ml), the organics were combined, dried over MgSO4, filtered and concentrated. The resulting crude oil was purified on 400 g silica (ethyl acetate/hexanes) to yield 29.9 g (82%) of 1-[(1,1-dimethylethyl)(dimethyl)silyl]-3,3-dimethyl-2-pyrrolidinone as a light yellow oil. LCMS (ESI+)=228 m/z (M+). 1H NMR (400 MHz CDCl3) δ 3.31-3.27 (t, 2H, J=6.68 Hz), 1.90-1.87 (t, 2H, J=6.79 Hz), 1.15 (s, 6H), 0.96 (s, 9H), 0.28 (s, 6H).

Provenance & Evidence