反应详情

A mixture of 0.98 g of 2-fluoro-4-[4-(methoxymethylidene)cyclohexyl]benzonitrile (U.S. Pat. No. 4,784,471), 0.70 g of 2-(1E-pentenyl)-1,3-propanediol, 45 ml of toluene, 2 ml of water and 10 drops of 10 percent sulphuric acid was stirred at about 85° C. for 75 minutes, then heated to boiling for 1 hour, whereby moist solvent distilled off and was replaced by fresh toluene. The reaction mixture was treated with 12 drops of triethylamine and, after cooling, washed three times with 15 ml of water, dried over sodium sulphate, filtered and concentrated. Chromatography of the residue (1.86 g) on 50 g of silica gel with hexane/ethyl acetate (vol. 9:1) and two-fold recrystallization from 8 ml of hexane each time gave 0.65 g of pure 2-fluoro-4-[trans-4-[trans-5-(1E-pentenyl)-1,3-dioxan-2-yl]cyclohexyl]benzonitrile, m.p. (C-N) 91.2° C., cl.p. (N-I) 192.5° C.

1. temperatureheated
2. distillationwhereby moist solvent distilled off
3. additionThe reaction mixture was treated with 12 drops of triethylamine
4. temperatureafter cooling
5. washwashed three times with 15 ml of water
6. dry with materialdried over sodium sulphate
7. filtrationfiltered
8. concentrationconcentrated
9. customChromatography of the residue (1.86 g) on 50 g of silica gel with hexane/ethyl acetate (vol. 9:1) and two-fold recrystallization from 8 ml of hexane each time