335255-43-1

General method: synthesis of tert-butyl (2-amino-4-(thiophen-2-yl)phenyl)carbamate (9a): compound 9a was prepared with reference to the method described in the patent literature (WO2009/055917). n-BOC-2-nitro-4-(2-thienyl)aniline (8a, 0.24 g, 0.75 mmol) was added to a round bottom flask with 10% palladium carbon catalyst (20 mg). The reaction system was replaced with hydrogen and the reaction was stirred for 2 h at room temperature in a hydrogen atmosphere (provided by the balloon). Upon completion of the reaction, the catalyst was removed by filtration through diatomaceous earth (Ceiite) and the filtrate was concentrated under reduced pressure to afford the target product (tert-butyl 2-amino-4-(thiophen-2-yl)phenyl)carbamate (9a, 0.217 g, 100% yield).1H NMR (400 MHz, CDCl3) δ 7.33-7.27 (m, 1H), 7.25-7.21 (m, 2H). 7.21 (m, 2H), 7.08-7.03 (m, 2H), 7.02 (d, J = 2.0 Hz, 1H), 1.52 (s, 9H).

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