反应详情

温度

0 °C

To 350 ml of bromochloromethane cooled to 0° C. is added 67 g (0.14 mole) tetrabutylammonium salt of benzyl adipate half ester and the mixture is stirred overnight at 0° C. then allowed to warm to room temperature. The excess bromochloromethane is evaporated in vacuo, 400 ml ethyl ether is added to the residue and the mixture is stirred to form crystals of tetrabutylammonium bromide. The crystals are removed by filtration, washed with ether, stirred with ethyl acetate (300 ml) for one hour and refiltered and washed with ethyl acetate. The combined filtrates are evaporated in vacuo, the residue purified by chromatography on silica gel (1 kg), eluting with 2:1 hexane/ethyl acetate, to yield 19.1 g (48%) of the title compound. 1H-NMR (CDCl3) ppm (delta): 1.58-1.9 (m, 4H), 2.2-2.62 (n, 4H), 5.13 (s, 2H), 5.68 (s, 2H), 7.38 (s, 5H).

1. temperatureto warm to room temperature
2. customThe excess bromochloromethane is evaporated in vacuo, 400 ml ethyl ether
3. additionis added to the residue
4. stirringthe mixture is stirred
5. customto form crystals of tetrabutylammonium bromide
6. customThe crystals are removed by filtration
7. washwashed with ether
8. stirringstirred with ethyl acetate (300 ml) for one hour
9. washwashed with ethyl acetate
10. customThe combined filtrates are evaporated in vacuo
11. customthe residue purified by chromatography on silica gel (1 kg)
12. washeluting with 2:1 hexane/ethyl acetate