[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[C:6]([OH:8])=[O:7].[C:9](Br)([CH3:12])([CH3:11])[CH3:10]>C(Cl)Cl>[CH3:10][C:9]([C:5]1[S:1][C:2]([C:6]([OH:8])=[O:7])=[CH:3][CH:4]=1)([CH3:12])[CH3:11]To a solution of 5.0 g (39.02 mmol) of thiophene-2-carboxylic acid (Aldrich Chemical Co.) in 100 mL of methylene chloride stirred at 0° C. was added 11 g (82.5 mmol) of AICl3 and 5.8 g (43.0 mmol) of t-butyl bromide. The solution was stirred at room temperature for 18 hours then poured into 100 mL of ice water, and the mixture was extracted with ether. The extracts were washed with brine and dried over MgSO4, then concentrated to give 3.33 g of the title product. MS (M+H)+ : 202. NMR (CDCl3) δ:1.42 (s, 9H), 6.89 (d, 1H, J=4 Hz), 7.72 (d, 1H, J=4 Hz).
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