[OH:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:13]3[CH:14]=[CH:15][S:16][C:12]=3[C:11]([CH:17]=O)=[CH:10][CH:9]=2)=[CH:4][CH:3]=1.Cl.[NH2:20][OH:21].N1C=CC=CC=1>CO.CCOCC>[OH:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:13]3[CH:14]=[CH:15][S:16][C:12]=3[C:11]([CH:17]=[N:20][OH:21])=[CH:10][CH:9]=2)=[CH:4][CH:3]=1To a 5 ml round bottom flask was added 4-(4-hydroxyphenyl)-1-benzothiophene-7-carbaldehyde (42.0 mg, 0.165 mmol), hydroxylamine hydrochloride (23 mg, 0.331 mmol), and anhydrous pyridine (0.027 ml, 0.331 mmol) in MeOH (1.0 ml) was brought to reflux for 1.5 h and then allowed to cool. The mixture was then diluted with ether, washed with water (2 ml) and the organic layer was dried over anhydrous Na2SO4 then passed through a silica plug. Concentration under reduced pressure produced 38 mg (85%) of product as white solid. Further purification by column chromatography (30% EtOAc-hexanes) afforded 22 mg of product suitable for analytical analysis: mp 229.5–230.5° C.; 1H NMR (300 MHz, DMSO-d6): δ 6.92 (2H, d, J=8.4 Hz), 7.41 (3H, appt), 7.49 (1H, d, J=5.7 Hz), 7.59 (1H, d, J=7.6 Hz), 7.85 (1H, d, J=5.6 Hz), 8.49 (1H, s), 9.68 (1H, s), 11.62 (1H, s); MS (ESI) m/z 268 ([M−H]).
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