Cesium carbonate → 8-chloro-5H-chromeno[3,4-c]pyridin-5-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-(4-chloro-2-fluorophenyl)nicotinic acid (0.3 g, 1.192 mmol) in anhydrous DMSO (1 mL) was added Cs2CO3 (0.388 g, 1.192 mmol) and the mixture was subjected to microwave heating for 2 h at 60° C. The reaction mixture was diluted with water and extracted with ethyl acetate (2×15 mL). The combined organic extracts were washed with water (1×15 mL) and brine (1×15 mL), dried over sodium sulfate and concentrated under reduced pressure to afford 8-chloro-5H-chromeno[3,4-c]pyridin-5-one (0.2 g, 0.863 mmol, 72% yield over 2 steps). 1H NMR (400 MHz, CDCl3) δ 9.57 (d, J=0.40 Hz, 1H), 8.98 (d, J=5.60 Hz, 1H), 8.01 (d, J=8.80 Hz, 1H), 7.88 (q, J=0.40 Hz, 1H), 7.44 (d, J=2.00 Hz, 1H), 7.39 (q, J=2.00 Hz, 1H); LCMS (ESI) m/e 232.6 [(M+H)+, calcd for C12H7ClNO2 232.0]; LCMS retention time (Method D): tR=0.81 min.

Provenance & Evidence