Sodium Carbonate → tert-Butyl 2-nitro-4-(thiophen-2-yl)phenylcarbamate

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Reaction Steps

A solution of tert-butyl 4-bromo-2-nitrophenylcarbamate 175 (3.97 g, 12.5 mmol), 2-thiophene boronic acid 176 (1.68 g, 13.4 mmol), sodium carbonate (3.98 g, 37.56 mmol) and Pd(PPh3)4 (0.94 g, 0.814 mmol) were stirred at 110° C. in a mixture of DME and water (2:1, 70 mL overnight. The solution was evaporated to dryness, diluted with water and extracted with ethyl acetate. The organic phase was washed with brine, dried over sodium sulfate, filtered and evaporated to provide the crude product which was purified by flash chromatography (10% ethyl acetate in hexane) to provide the title compound 177 (2.14 g, 53% yield). 1H NMR: (DMSO) δ (ppm): 400 MHz, (DMSO) d (ppm): 9.63 (s, 1H), 8.12 (d, J=2.3 Hz, 1H), 7.92 (dd, J=8.4, 2.2 Hz, 1H), 7.66 (d, J=8.4 Hz, 1H), 7.61 (q, J=2.2 Hz, 2H), 7.15 (dd, J=5.1, 3.7 Hz, 1H), 1.46 (s, 9H). MS: (calc.) 320.08; (obt.) 343.1 (M+Na).

Provenance & Evidence