反应详情

To a 10 mL round-bottom flask with 3-hydroxy-4-methylbenzoic acid (2.5 g, 16.4 mmol), was added SOCl2 (15 mL) dropwise. The reaction was refluxed for 30 min, cooled to rt. The excess of SOCl2 was removed in vacuo and the oily acid chloride was dissolved in THF (15 mL). The resulting solution was added dropwise to a mixture of 2-aminophenol (1.8 g, 16.4 mmol), triethylamine (1.7 g, 16.4 mmol) and THF (30 mL) at 0° C. The reaction mixture was brought to rt for 30 min, after which time, the precipitate was filtered. The filtrate was concentrated and dried in vacuo. The dark brown solid residue was dissolved in toluene (20 mL) and p-toluenesulfonic acid (15.6 g, 82 mmol) was added. The mixture was refluxed overnight, cooled to rt and EtOAc (500 mL) was added. The EtOAc solution was washed with brine (3×50 mL), dried (MgSO4), filtered, and concentrated in vacuo. The residue was recrystallized in EtOAc to afford 5-(1,3-benzoxazol-2-yl)-2-methylphenol as a light yellow solid. MS (ESI) 226(M+H)+.

1. temperatureThe reaction was refluxed for 30 min
2. customThe excess of SOCl2 was removed in vacuo
3. dissolutionthe oily acid chloride was dissolved in THF (15 mL)
4. filtrationafter which time, the precipitate was filtered
5. concentrationThe filtrate was concentrated
6. customdried in vacuo
7. dissolutionThe dark brown solid residue was dissolved in toluene (20 mL)
8. temperatureThe mixture was refluxed overnight
9. temperaturecooled to rt
10. washThe EtOAc solution was washed with brine (3×50 mL)
11. dry with materialdried (MgSO4)
12. filtrationfiltered
13. concentrationconcentrated in vacuo
14. customThe residue was recrystallized in EtOAc