反应详情

3-Methoxy-4-pyridin-2-yl benzoic acid (490 mg, 2.1 mmol), 2-amino-p-cresol (527 mg, 4.28 mmol) and trimethylsilyl polyphosphate (2 mL) was refluxed overnight under argon. Added water (100 mL) to the cooled reaction mixture and basified to pH 8 (solid NaHCO3). Extracted with EtOAc (3×60 mL), dried (Na2SO4) and concentrated in vacuo. The resulting yellow residue was purified by flash chromatography using a gradient elution of 1:9 EtOAc:hexanes to 1:4 EtOAc:hexanes to give the desired compound, 2-(3-methoxy-4-pyridin-2-ylphenyl)-5-methyl-1,3-benzoxazole, as a yellow solid. 1H NMR (CDCl3, 300 MHz) δ 8.74 (m, 1H), 7.98–7.16 (m, 10H), 4.03 (s, 3H), 2.51 (s, 3H). (ESI) 317 (M+H)+.

1. extractionExtracted with EtOAc (3×60 mL)
2. dry with materialdried (Na2SO4)
3. concentrationconcentrated in vacuo
4. customThe resulting yellow residue was purified by flash chromatography
5. washa gradient elution of 1:9 EtOAc