Dimethylformamide → Di-tert-butyl [2-(ethoxycarbonyl)-1-benzothien-6-yl](fluoro)malonate

Participants

Reaction Conditions

Reaction Steps

To a suspension of sodium hydride (0.96 g, 24.0 mmol) in THF (75 mL) cooled to 0° C. was added a solution of di-tert-butyl[2-(ethoxycarbonyl)-1-benzothien-6-yl]malonate (described above) (9.66 g, 23.0 mmol) in THF (150 mL) under nitrogen. The resulting orange solution was stirred at 4° C. for 15 minutes. DMF (225 mL) was added followed by Selectfluor (8.15 g, 23.0 mmol). The reaction was warmed to ambient temperature and stirred for 4 hours under nitrogen. The reaction was quenched with ammonium chloride solution and partitioned between ethyl acetate and water. The organics were washed with water and brine, dried over magnesium sulfate, filtered and evaporated in vacuo. Purification by flash column chromatography (2-20% ethyl acetate/hexanes) gave a mixture of starting material and product. This was resubjected to above reaction conditions and purified in a similar manner to give a pale yellow solid. 1H NMR (DMSO-d6) δ 8.21 (s, 1H), 8.17 (s, 1H), 8.07 (d, J=8.8 Hz, 1H), 7.52 (d, J=9.1 Hz, 1H), 4.33 (q, J=7.3 Hz, 2H), 1.44 (s, 18H), 1.31 (t, J=7.0 Hz, 3H).

Provenance & Evidence