Cesium carbonate → tert-butyl 8-(3-fluorophenylsulfonyl)-3,4-dihydrobenzofuro[3,2-c]pyridine-2(1H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of product of step B (300 mg, 0.85 mmol), sodium 3-fluorobenzenesulfinate (186 mg, 1.02 mmol), di-palladium-tris(dibenzylideneacetone) (78 mg, 0.08 mmol), cesium carbonate (416 mg, 1.28 mmol) and xantphos (99 mg, 0.17 mmol) was suspended in anhydrous toluene (4.5 mL). The reaction flask was purged with argon, sealed and heated to 120° C. for 14 h. The reaction mixture was cooled to ambient temperature, diluted with dichloromethane and filtered through a celite bed. The filtrate was concentrated in vacuo to give the crude product which was purified by flash column chromatography (SiO2, 3:2 hexanes/ethyl acetate) providing tert-butyl 8-(3-fluorophenylsulfonyl)-3,4-dihydrobenzofuro[3,2-c]pyridine-2(1H)-carboxylate (135 mg, 37%) as a pale yellow solid: 1H NMR (CDCl3, 300 MHz) δ 8.08 (s, 1H), 7.83 (dd, J=8.7, 1.8 Hz, 1H), 7.77-7.72 (m, 1H), 7.65 (dt, J=7.8, 2.1 Hz, 1H), 7.53 (d, J=8.4 Hz, 1H), 7.51-7.44 (m, 1H), 7.25-7.20 (m, 1H), 4.58 (s, 2H), 3.84 (t, J=5.4 Hz, 2H), 2.91-2.84 (m, 2H), 1.55 (s, 9H).

Provenance & Evidence