Water → 4-(2,2-Difluoro-benzo[1,3]dioxol-5-ylmethyl)-piperazine-1-carboxylic acid pyridin-3-ylamide

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Reaction Steps

To a solution of pyridine-3-yl-carbamic acid phenyl ester (9.08 g, 42.4 mmol) in DMSO (84 mL) was added 1-(2,2-difluoro-benzo[1,3]dioxol-5-ylmethyl)-piperazine (11.4 g, 44.5 mmol). The reaction mixture was stirred at room temperature for 16 h, then treated with water (130 mL). The resulting solid was isolated by filtration, rinsed with water (4×50 mL) and dried under vacuum. The solid was recrystallized (EtOH—H2O) to give 4-(2,2-difluoro-benzo[1,3]dioxol-5-ylmethyl)-piperazine-1-carboxylic acid pyridin-3-ylamide (13.4 g, 84%). MS (ESI+): calcd for C18H18F2N4O3 m/z 376.13. found 377.1 (M+H)+. 1H NMR (CDCl3): 8.46 (d, J=2.5 Hz, 1H), 8.23-8.21 (m, 1H), 7.99-7.96 (m, 1H), 7.22-7.19 (m, 2H), 7.11 (s, 1H), 6.99-6.98 (m, 2H), 3.54-3.52 (m, 4H), 3.49 (s, 2H, 2.46-2.44 (m, 4H).

Provenance & Evidence