反应详情

温度

110 °C

Dry N,N-dimethylformamide (34.2 ml, 444 mmol) was added dropwise with stirring and cooling under an argon atmosphere to phosphorous oxychloride (18.3 ml, 200 mmol) at such a rate that the temperature did not exceed 10° C. After 30 min stirring at 0° C., a solution of 1-benzyloxy-3-methyl-benzene (22 g, 111 mmol) in N,N-dimethylformamide (22 ml) was added dropwise within 30 min (for the preparation of 1-benzyloxy-3-methyl-benzene see: D. Bogdal, J. Pielichowski, A. Boron, Syn. Commun. 1998, 28, 3029-3039). The reaction mixture was stirred 30 min at ambient temperature and then continuously heated to 110° C. After 10 min at 110° C., the mixture was kept at 90° C. for 3.5 h, cooled to 10° C., neutralized with 25% aqueous sodium acetate, with cooling, and extracted with ethyl acetate. The combined organic layers were washed with saturated aqueous sodium bicarbonate and brine and dried over sodium sulfate. Removal of the solvent under reduced pressure gave a brown oil which was purified by column chromatography (silica gel, hexane/AcOEt=19/1) to give 4.3 g (19 mmol, 17%) of the title compound as yellow solid.

1. customdid not exceed 10° C
2. stirringAfter 30 min stirring at 0° C.
3. stirringThe reaction mixture was stirred 30 min at ambient temperature
4. waitthe mixture was kept at 90° C. for 3.5 h
5. temperaturecooled to 10° C.
6. temperaturewith cooling
7. extractionextracted with ethyl acetate
8. washThe combined organic layers were washed with saturated aqueous sodium bicarbonate and brine
9. dry with materialdried over sodium sulfate
10. customRemoval of the solvent under reduced pressure
11. customgave a brown oil which
12. customwas purified by column chromatography (silica gel, hexane/AcOEt=19/1)