Cesium carbonate → 2-(Fluoromethyl)-1-methyl-4-(6-nitropyridin-3-yl)piperazine

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Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged with 111d (1.6 g, 12.1 mmol), 5-bromo-2-nitropyridine (3.7 g, 18.2 mmol) and cesium carbonate (9.9 g, 30.2 mmol). After bubbling nitrogen through the resulting solution for 30 min, xantphos (700 mg, 0.12 mmol) and tris(dibenzyl-ideneacetone)dipalladium(0) (550 mg, 0.06 mmol) were added, and the reaction mixture was heated at reflux for 15 h. After this time the reaction was cooled to room temperature, filtered and concentrated to afford a black solid as the crude product. Then it was purified on silica gel (DCM: MeOH=100:1) to afford 111e as a yellow solid (2.6 g, yield 76%). 1H NMR (500 MHz, MeOD) δ 8.20 (dd, J=12.5 Hz, 2H), 7.51 (dd, J=9.0 Hz, 1H), 4.74-4.54 (m, 2H), 4.03-3.92 (m, 2H), 3.20 (m, 1H), 3.09-2.99 (m, 2H), 2.50 (m, 2H), 2.46 (s, 3H),

Provenance & Evidence