[CH2:1]([Li])[CH2:2][CH2:3][CH3:4].BrC1C2[O:14][C:13]([C:16]3[CH:21]=[CH:20][C:19]([O:22][CH3:23])=[CH:18][CH:17]=3)=[N:12][C:11]=2[CH:10]=[C:9]([O:24][CH3:25])[CH:8]=1.ICC>C1COCC1>[CH2:3]([C:2]1[C:1]2[O:14][C:13]([C:16]3[CH:17]=[CH:18][C:19]([O:22][CH3:23])=[CH:20][CH:21]=3)=[N:12][C:11]=2[CH:10]=[C:9]([O:24][CH3:25])[CH:8]=1)[CH3:4]n-Butyllithium (2.5 N, 0.43 mL, 1.08 mmol) was added dropwise into a cold (−78° C.) mixture of 7-bromo-5-methoxy-2-(4-methoxyphenyl)-1,3-benzoxazole (300 mg, 0.90 mmol) and THF (2 mL). The mixture was allowed to stir for 0.5 h. Iodoethane (0.14 mL, 1.8 mmol) was added dropwise into the mixture. The reaction mixture was allowed to warm to room temperature and stirred for 2 h. The reaction was quenched with aqueous ammonium chloride, poured into water, and extracted with EtOAc. The organic extracts were washed with brine and dried over MgSO4. Evaporation and flash chromatography (20% EtOAc/petroleum ether) gave (231 mg, 91% yield) of the product as a light brown solid: m.p. 85° C.; MS m/e 284 (M+H)+.
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