Phosphorus oxychloride → 7-Chlorothieno[3,2-b]pyridine-6-carbonitrile

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Reaction Steps

A stirred mixture of 7-oxo-4,7-dihydro-thieno[3,2-b]pyridine-6-carbonitrile (0.668 g, 3.8 mmol) and 6 ml of phosphorus oxychloride was heated to reflux for 2 h, and then cooled to room temperature. The residue was added to ice water and dichloromethane, and the resulting mixture was neutralized by addition of solid NaHCO3 carefully. The organic layer was separated, washed with H2O, dried over MgSO4, and concentrated in vacuum to give 0.526 g (71%) of a red-brown solid. 1H NMR (300 MHz, DMSO-d6) δ 9.12 (s, 1H), 8.60 (d, J=5.4 Hz, 1H), 7.82 (d, J=6 Hz, 1H); LC-MS (ESI) m/z 195.0 (M+1).

Provenance & Evidence