CC(C)(C)OC(N)=O.O=Cc1ccc(Br)cc1F>Cc1ccccc1.O=C(/C=C/c1ccccc1)/C=C/c1ccccc1.O=C(/C=C/c1ccccc1)/C=C/c1ccccc1.O=C([O-])[O-].[Cs+].[Cs+].[Pd].c1ccc(P(c2ccccc2)c2ccc3ccccc3c2-c2c(P(c3ccccc3)c3ccccc3)ccc3ccccc23)cc1>CC(C)(C)OC(=O)Nc1ccc(C=O)c(F)c1
A solution of 4-bromo-2-fluorobenzaldehyde (0.670 g, 3.30 mmol) dissolved in toluene (10 mL) was treated with tert-butyl carbamate (0.464 g, 3.96 mmol), rac-2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl (0.164 g, 0.26 mmol), Bis(dibenzylideneacetone)palladium (0.076 g, 0.13 mmol) and cesium carbonate (1.527 g, 4.69 mmol) under nitrogen. The mixture was degassed under vacuum several times before heating at 100 °C for 24 hours. Reaction incomplete so heated for further 10 hours. The reaction mixture was diluted with water (250 mL), and extracted with ethyl acetate (250 mL X 2). The organic was dried over magnesium sulfate, filtered and evaporated to afford crude product. The crude product was purified by flash silica chromatography, elution 10% ethyl acetate in isohexane. Pure fractions were evaporated to dryness to afford tert-butyl 3-fluoro-4-formylphenylcarbamate (0.660 g, 84 %) as a yellow solid.
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