反应详情

140.9 g of 2-(1,3-dioxolan-2-yl)ethyl-triphenylphosphonium bromide were suspended in 4.5 1 of tetrahydrofuran while gassing with nitrogen and the suspension was treated at 0° C. within 5 minutes with 36.8 g of potassium tert.butylate. The orange suspension was stir-red at room temperature for a further I hour and treated within 5 minutes with 46.1 g of 4-(4-oxocyclohexyl)benzamide. The reaction mixture was stirred at room temperature for a further 4.5 hours and then concentrated in a vacuum. The yellowish crystals obtained (212.5 g) were treated with 1.2 1 of diethyl ether. The mixture was stirred at room temperature for 30 minutes and then suction filtered. The residue was washed with diethyl ether and then suspended in 700 ml of water. The mixture was stirred for 15 minutes and then suction filtered. The residue was washed with water and dissolved while heating in 600 ml of dioxan. The solution was left to cool to room temperature. The separated crystals were removed by filtration under suction, washed with a small amount of dioxan and hexane and dried at 60° C. in a vacuum, whereby there were obtained 39.2 g of crystalline 4-[4-[2-(1,3-dioxolan-2-yl)ethylidene]cyclo-hexyl]benzamide with m.p. 209°-212° C. Working-up of the mother liquor (72.6 g) gave a further 7.7 g of product and 64.2 g of a second mother liquor.

1. customwas stir-red at room temperature for a further I hour
2. concentrationconcentrated in a vacuum
3. customThe yellowish crystals obtained (212.5 g)
4. stirringThe mixture was stirred at room temperature for 30 minutes
5. filtrationsuction filtered
6. washThe residue was washed with diethyl ether
7. stirringThe mixture was stirred for 15 minutes
8. filtrationsuction filtered
9. washThe residue was washed with water
10. dissolutiondissolved
11. temperaturewhile heating in 600 ml of dioxan
12. waitThe solution was left
13. temperatureto cool to room temperature
14. customThe separated crystals were removed by filtration under suction
15. washwashed with a small amount of dioxan and hexane
16. customdried at 60° C. in a vacuum