反应详情

5-Amino-4-(2′-methyl-biphenyl-3-sulfonyl)-thiophene-2-carboxylic acid methyl ester was prepared following the procedure as in Example 1: step c using 5-amino-4-(3-bromo-benzenesulfonyl)-thiophene-2-carboxylic acid methyl ester (598.9 mg, 1.6 mmol) (Example 20: steps a–c), o-tolyl-phenyl boronic acid (435.6 mg, 3.2 mmol), Pd(PPh3)4 (366.6 mg, 0.32 mmol), aqueous Na2CO3 (2M, 6.4 mL, 12.8 mmol), ethanol (6.4 mL) and toluene (12.8 mL). Purification by flash column chromatography (Biotage Flash™ System—40 M SiO2 column) (25% EtOAc in hexanes) of the residue yielded the adduct (137 mg, 23%) as a light brown solid. ESI-MS (m/z): Calcd. for C19H17NO4S2: 387.02; found: 388.3. 5-Amino-4-(2′-methyl-biphenyl-3-sulfonyl)-thiophene-2-carboxylic acid methyl ester (61 mg, 16 mmol) was then converted to the amidine and purified as described in Example 20: step f to isolate the title compound (6 mg, 10%) as a light brown solid. 1H-NMR (CD3OD): δ: 7.96–7.99 (m, 1H), 7.95 (s, 1H), 7.93–7.94 (m, 1H), 7.63–7.69(m, 3H), 7.18–7.32 (m, 3H), 2.22 (s, 3H). ESI-MS (m/z): Calcd. for C18H17N3O2S2: 372.0 (M+H); found: 372.2.

1. customPurification by flash column chromatography (Biotage Flash™ System—40 M SiO2 column) (25% EtOAc in hexanes) of the residue