[CH3:1][CH2:2][O:3][C:4]([C:6]1[S:10][C:9]2[CH:11]=[C:12]([C:15](O)=[O:16])[CH:13]=[CH:14][C:8]=2[CH:7]=1)=[O:5]>C1COCC1>[CH2:2]([O:3][C:4]([C:6]1[S:10][C:9]2[CH:11]=[C:12]([CH2:15][OH:16])[CH:13]=[CH:14][C:8]=2[CH:7]=1)=[O:5])[CH3:1]A solution of benzo[b]thiophene-2,6-dicarboxylic acid 2-ethyl ester (1.6 g, 6.4 mmol) in anhydrous THF (40 mL, 25 vol) was cooled to 0° C. To this BH3 (1M in THF, 30 mL, 30.0 mmol) was added slowly. The reaction was allowed to warm to r.t. and stirred for 3 h. The solution was then cooled to 0° C. and quenched using 1N HCl (7.5 mL). The reaction mixture was concentrated under vacuum to remove all THF and the resulting solid isolated by filtration and dried under vacuum to give 6-hydroxymethyl-benzo[b]thiophene-2-carboxylic acid ethyl ester (1.3 g, 87%). LCMS m/z 237 [M++H]+, 1H NMR (300 MHz, DMSO), δ: 1.34 (3H, t J=6.9 Hz, CH3), 4.35 (2H, q J=7.1 Hz, CH2), 4.65 (2H, s, CH2), 6.53 (1H, br s, OH), 7.42 (1H, d J=9.4 Hz), 7.98 (3H, m, ArH), 8.18 (1H, s, ArH).
불러오는 중…