Phosphorus trichloride → HCID 136338372, compound

Participants

Reaction Steps

To a N,N-dimethylformamide (6 mL) suspension of sodium hydride (97%, 0.144 g, 6.0 mmol) was added 2-oxoindoline-6-carbonitrile (0.712 g, 4.5 mmol). The formed mixture was stirred for 10 min at room temperature followed by the addition of ethyl 6-chloronicotinate 1-oxide (0.605 g, 3.0 mmol). The resulting reaction mixture was set under N2 atmosphere and stirred for 2 h at room temperature. The N,N-dimethylformamide reaction solution was diluted with a saturated aqueous sodium hydrogen carbonate solution and extracted with chloroform and ethyl acetate. The combined organic layers were dried (Na2SO4) and concentrated in vacuo. The remaining N,N-dimethylformamide was removed by co-evaporation with toluene. The residue was dissolved in chloroform (10 mL) and phosphorus trichloride (1.65 g, 12.0 mmol) was added. The reaction mixture was stirred for 30 min at 60° C. and then cooled to room temperature. The mixture was poured into a saturated aqueous sodium hydrogen carbonate solution. The resulting brown precipitate was filtered off and the mother liquor was extracted with chloroform (4×). The organic layers were concentrated in vacuo and the residue was combined with the filtrate and was washed with ethyl acetate and diethyl ether to afford 0.55 g (60% yield) of the title compound as a yellow-brown solid: 1H NMR (DMSO-d6, 400 MHz) δ 8.85 (s, 1H), 8.06 (s, 1H), 8.00 (d, J=8.8 Hz, 1H), 7.75 (d, J=8.0 Hz, 1H), 7.69 (d, J=8.0 Hz, 1H), 7.45 (s, 1H), 7.29 (d, J=8.8 Hz, 1H), 4.33 (m, 2H), 1.35 (t, J=7.2 Hz, 3H); MS (EI) m/z 308 (M++1).

Provenance & Evidence