反应详情

To a mixed suspension of magnesium (305 mg, 12.6 mmol) in diethyl ether (7.5 mL) and toluene (7.5 mL) was added bromine (354 μL, 6.91 mmol) at 0° C., which was stirred at room temperature for 5 minutes under nitrogen atmosphere and was refluxed while heating for 5 minutes. After the reaction mixture was cooled to room temperature, a toluene (20 mL) solution of 2,5-bis-benzyloxy-benzaldehyde (2.00 g, 6.28 mmol) described in Production Example 7-1-1 were added followed by stirring at room temperature for 24 hours under nitrogen atmosphere. Moreover, after stirring for 6 hours while refluxing while heating, the reaction mixture was cooled to room temperature. The precipitated solid was filtered out and washed with toluene. 1 N aqueous hydrochloric acid solution (20 mL) was added to the filtered solid followed by stirring for 1 hour while refluxing and heating. The reaction solution was allowed to cool to room temperature followed by extraction with ethyl acetate. The organic layer was washed with sat. NaCl followed by drying over anhydrous magnesium sulfate and filtering. The filtrate was concentrated under a reduced pressure and the residue was purified by silica gel column chromatography (heptane:ethyl acetate=1:1) to obtain the title compound (830 mg, 58%) as a pale yellow solid.

1. temperaturewas refluxed
2. temperaturewhile heating for 5 minutes
3. temperatureAfter the reaction mixture was cooled to room temperature
4. additionwere added
5. stirringby stirring at room temperature for 24 hours under nitrogen atmosphere
6. stirringMoreover, after stirring for 6 hours
7. temperaturewhile refluxing
8. temperaturewhile heating
9. temperaturethe reaction mixture was cooled to room temperature
10. filtrationThe precipitated solid was filtered out
11. washwashed with toluene
12. addition1 N aqueous hydrochloric acid solution (20 mL) was added to the filtered solid
13. stirringby stirring for 1 hour
14. temperaturewhile refluxing
15. temperatureheating
16. temperatureto cool to room temperature
17. extractionfollowed by extraction with ethyl acetate
18. washThe organic layer was washed with sat. NaCl
19. dry with materialby drying over anhydrous magnesium sulfate
20. filtrationfiltering
21. concentrationThe filtrate was concentrated under a reduced pressure
22. customthe residue was purified by silica gel column chromatography (heptane:ethyl acetate=1:1)