反应详情

The reaction flask was charged under argon with 3.45 g of magnesium (142 mmol). A solution of 21.16 g of methyl iodide (147 mmol) in 120 mL of tert-butyl-methyl-ether was added during 45 min at 45° C. under stirring. Then stirring was continued for 1 h at 45° C. and then a solution of 27.12 g of 4-benzyloxyacetophenone (120 mmol) in 100 mL of tetrahydrofuran was added during 45 min., while a temperature of 45° C. was again maintained. Stirring at 45° C. was continued for 1.5 h. After cooling to room temperature, the white suspension was poured into a mixture of 100 mL of 10% aqueous ammonium chloride and of ice and extracted with 150 mL of ethyl acetate. The aqueous phase was separated and extracted with 100 mL of ethyl acetate. The organic phase was washed with 120 mL of 20% aq. sodium chloride, combined, dried (MgSO4) and evaporated under reduced pressure to give 29.9 g of crude product as an oil which partially crystallised. The crude product was taken up in 30 mL of dichloromethane. The solution was concentrated at the rotary evaporator almost to dryness. Then 6 mL of ethyl acetate was added followed by gradual addition of a total of 180 mL of hexane. The suspension was then kept at 0° C. for 30 min. The crystals were collected and washed with cold hexane. After drying for 2 h at 16 mbar/45° C., 26.7 g (92%) 2-(4-benzyloxy-phenyl)-propan-2-ol was obtained.

1. stirringThen stirring
2. temperaturewas again maintained
3. stirringStirring at 45° C.
4. waitwas continued for 1.5 h
5. extractionextracted with 150 mL of ethyl acetate
6. customThe aqueous phase was separated
7. extractionextracted with 100 mL of ethyl acetate
8. washThe organic phase was washed with 120 mL of 20% aq. sodium chloride
9. dry with materialdried (MgSO4)
10. customevaporated under reduced pressure
11. customto give 29.9 g of crude product as an oil which
12. custompartially crystallised
13. concentrationThe solution was concentrated at the rotary evaporator almost to dryness
14. additionThen 6 mL of ethyl acetate was added
15. additionfollowed by gradual addition of a total of 180 mL of hexane
16. waitThe suspension was then kept at 0° C. for 30 min
17. customThe crystals were collected
18. washwashed with cold hexane
19. customAfter drying for 2 h at 16 mbar/45° C.