2-Aminophenol → 5-(1,3-Benzoxazol-2-yl)-2-methylphenol

To a 100 mL round-bottom flask with 3-hydroxy-4-methylbenzoic acid (2.5 g, 16.4 mmol) was added SOCl2 (15 mL) dropwise. This reaction was refluxed for 30 min, cooled to rt and the excess SOCl2 removed in vacuo. The oily acid chloride was dissolved in THF (15 mL) and the solution was added dropwise to a mixture of 2-aminophenol (1.8 g, 16.4 mmol), triethylamine (1.7 g, 16.4 mmol) in THF (30 mL) at 0° C. The reaction was then brought to rt for 0.5 h and the precipitate was removed by filtration. The filtrate was concentrated and dried in vacuo. To the dark brown solid residue was added toluene (20 mL) and p-toluenesulfonic acid (15.6 g, 82 mmol). The reaction was refluxed overnight, cooled to rt and dissolved in EtOAc (500 mL). The EtOAc solution was washed with H2O (3×5 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. temperatureThis reaction was refluxed for 30 min
2. customthe excess SOCl2 removed in vacuo
3. dissolutionThe oily acid chloride was dissolved in THF (15 mL)
4. customthe precipitate was removed by filtration
5. concentrationThe filtrate was concentrated
6. customdried in vacuo
7. temperatureThe reaction was refluxed overnight
8. temperaturecooled to rt
9. washThe EtOAc solution was washed with H2O (3×5 mL)
10. dry with materialdried (MgSO4)
11. filtrationfiltered
12. concentrationconcentrated in vacuo
13. customThe residue was recrystallized in EtOAc

ORD record

ord-4fb7e24f521c44f0ab2773f5aa4bbcbd

Source dataset

uspto-grants-2006_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07087601B2