Phosphorus oxychloride → Benzyl 4-(8-chloroimidazo[1,5-a]pyrazin-3-yl)piperidine-1-carboxylate

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Reaction Steps

To a suspension of benzyl 4-{[(3-chloropyrazin-2-yl)methyl]carbamoyl}piperidine-1-carboxylate (0.100 g, 0.220 mmol) in EtOAc (0.9 mL) and DMF (0.068 mL) at 0° C. was slowly added POCl3 (0.082 mL, 0.88 mmol). After stirring at rt for an hour the mixture was cooled to 0° C. then treated with solid NaHCO3 The mixture was stirred for 20 min at rt, diluted with water and extracted with EtOAc (3×20 mL). The combined extracts were washed with water (2×30 mL) and brine (30 mL), then dried over Na2SO4, and concentrated in vacuo to yield 2.07 g of desired product. 1H NMR (400 MHz, CDCl3): δ 1.98-2.04 (m, 4H), 3.03-3.20 (m, 3H), 4.30-4.33 (m, 2H), 5.16 (s, 2H), 7.33 (d, J=5.2 Hz, 1H), 7.35-7.38 (m, 5H), 7.26 (d, J=4.4 Hz, 1H), 7.79 (s, 1H). MS (ES+): m/z 371.22 [MH+].

Provenance & Evidence