[CH:1]([C:3]1[CH:4]=[CH:5][C:6]([O:12][CH3:13])=[C:7](B(O)O)[CH:8]=1)=[O:2].[CH3:14][C:15]1[O:16][C:17]2[CH:23]=[CH:22][C:21](Br)=[CH:20][C:18]=2[N:19]=1.C([O-])([O-])=O.[K+].[K+]>C(O)C.C1(C)C=CC=CC=1>[CH3:13][O:12][C:6]1[CH:5]=[CH:4][C:3]([CH:1]=[O:2])=[CH:8][C:7]=1[C:21]1[CH:22]=[CH:23][C:17]2[O:16][C:15]([CH3:14])=[N:19][C:18]=2[CH:20]=1
A solution of 5-formyl-2-methoxybenzeneboronic acid (1 g, 5.6 mmol), 2-methyl-5-bromobenzoxazole (1 g, 4.72 mmol) and K2CO3 (1.63 g, 11.8 mmol) in ethanol (20 mL) and toluene (40 mL) was degassed prior to addition of Pd(Ph3)4 (55 mg, 0.047 mmol). The mixture was refluxed for 20 hours then cooled and filtered through diatomaceous earth. The filtrate was concentrated in vacuo, extracted with ethyl acetate, washed with water and the organic layer dried over sodium sulphate. The crude was purified by column chromatography (heptane/ethyl acetate 7/3 to 6/4) to give 1.13 g of title compound.
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