Diethyl Pyrocarbonate → N-(4-(trifluoromethyl)-2-(piperidin-1-yl)benzyl)-2,3-dihydro-2-oxobenzo[d]oxazole-4-carboxamide

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Reaction Conditions

Reaction Steps

2,3-dihydro-2-oxobenzo[d]oxazole-4-carboxylic acid 21 (560 mg, 3.1 mmol) was dissolved in 20 ml of THF and at 0° C. DEPC (0.55 ml, 1.2 equiv) and amine 2c (964 mg, 1.2 equiv.) were added to the solution. The mixture was warmed at 80° C. overnight, then evaporated and the crude was dissolved in AcOEt (30 ml) and washed with water (1×20 ml) and brine. The organic phase was dried over sodium sulfate and concentrated under vacuum. The purification of the crude residue by chromatographic column using AcOEt 4/petroleum ether 6 as eluant gave 250 mg of a pale yellow solid. Yield=19% 1HNMR (DMSO, 200 MHz) δ 4.58 (2H, d, J=5.8 Hz), 7.14 (1H, t, J=8 Hz), 7.41 (4H, m), 7.68 (1H, dd, J=8 Hz, J′=0.8 Hz), 9.20 (1H, bt), 11.59 (1H, bs); [M+1] 420.2 (C21H20F3N3O3 requires 419.4).

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