Br[C:2]1[C:10]2[S:9][CH:8]=[CH:7][C:6]=2[C:5]([C:11]2[CH:16]=[CH:15][C:14]([O:17][CH3:18])=[CH:13][CH:12]=2)=[CH:4][CH:3]=1.[Li]CCCC.CN([CH:27]=[O:28])C.COC1C=CC(C2C3C=C(C=O)SC=3C=CC=2)=CC=1>C1COCC1>[CH3:18][O:17][C:14]1[CH:15]=[CH:16][C:11]([C:5]2[C:6]3[CH:7]=[CH:8][S:9][C:10]=3[C:2]([CH:27]=[O:28])=[CH:3][CH:4]=2)=[CH:12][CH:13]=1To a 25 ml round bottom flask was added 7-bromo-4-(4-methoxyphenyl)-1-benzothiophene (300 mg, 0.94 mmol) to anhydrous THF (10 ml) and the solution was cooled to −78° C. n-BuLi (0.38 ml of 2.5 M in hexanes, 0.94 mmol) was added dropwise and the solution was stirred for 10 min after which anhydrous DMF (0.15 ml, 1.9 mmol) was added all at once at −78° C. The reaction was stirred for 15 min then quenched with water (10 ml) and extracted with ether. The organic layers were combined, dried over anhydrous Na2SO4, and concentrated to 180 mg (71.4%) of aldehyde products as a yellow oil. Reverse phase HPLC (CH3CN 0.1% TFA, water 0.1% TFA) produced 160 mg of a 8:3 mixture of desired product and 4-(4-methoxyphenyl)-1-benzothiophene-2-carbaldehyde as a single peak. Another side product (7-bromo-4-(4-methoxyphenyl)-1-benzothiophene-2-carbaldehyde, 20 mg) was collected: 1H NMR (8:3 ratio of desired+7-bromo-4-(4-methoxyphenyl)-1-benzothiophene-2-carbaldehyde) (300 MHz, DMSO-d6): δ 3.86 (3H, s, desired+minor), 7.14 (2H, d, J=8.9 Hz, minor), 7.14 (2H, d, J=8.6 Hz, desired), 7.47 (1H, d, J=7.3 Hz, minor), 7.54–7.67 (4H, m, desired+minor), 7.99 (1H, d, J=5.6 Hz, desired), 8.09 (1H, d, J=8.1 Hz, minor), 8.19 (1H, d, J=7.5 Hz), 8.41 (1H, s, minor), 10.14 (1H, s, minor), 10.27 (1H, s, desired). Anal. for C16H12O2S:
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