Methyl iodide → 5-methyl-6,7-dihydro-1-benzothiophen-4(5H)-one

Participants

Reaction Steps

To a solution of 6,7-dihydro-1-benzothiophen-4(5H)-one (1.63 g) in tetrahydrofuran (90 ml) at −78° C. under N2 was added lithium diisopropyl amide (5.89 ml, 2 M). After 30 min, iodomethane (0.732 ml) was added and the reaction was allowed to warm to ambient temperature. After 2 h, the reaction mixture was poured into saturated sodium bicarbonate (100 ml), extracted methylene chloride (3×100 ml), dried MgSO4, filtered and concentrated. MPLC was run on a biotage 40M column with 4-6% ethyl acetate/heptane to provide the title compound as an oil (560 mg, 32%): 1H NMR (300 MHz, CDCl3) δ) 7.41, 7.08, 3.15-2.99, 2.61-2.53, 2.33-2.25, 2.06-1.92, 1.28; HRMS (FAB) calcd for C9H10OS+H 167.0531, found 167.0527.

Provenance & Evidence