反应详情

温度

0 °C

A solution of 5.6 g of 1,2-difluoro-4-[4-(methoxymethylidene)cyclohexyl]benzene in 125 ml of tetrahydrofuran/2N hydrochloric acid (vol. 4:1) was heated to 90° C. for 1.25 hours. The reaction mixture was subsequently poured on to ice-water and extracted with diethyl ether. The ether phase was washed neutral with 50 ml of semi-saturated sodium hydrogen carbonate solution and with two 50 ml portions of water, dried over sodium sulphate and concentrated. A solution of the resulting crude trans/cis mixture (5.1 g) in 25 ml of methanol was added dropwise in an inert gas atmosphere at 0°-3° C. within 5 minutes to 70 ml of 0.1N methanolic potassium hydroxide solution. The reaction mixture was stirred at 0° C. for 1 hour, then poured on to 200 ml of ice-water and extracted with diethyl ether. The ether phases were washed neutral with water, dried over sodium sulphate and concentrated. There were obtained 4.8 g of trans-4-(3,4-difluorophenyl)cyclohexanecarboxaldehyde (cis content 5.7%).

1. extractionextracted with diethyl ether
2. washThe ether phase was washed neutral with 50 ml of semi-saturated sodium hydrogen carbonate solution and with two 50 ml portions of water
3. dry with materialdried over sodium sulphate
4. concentrationconcentrated
5. additionA solution of the resulting crude trans/cis mixture (5.1 g) in 25 ml of methanol was added dropwise in an inert gas atmosphere at 0°-3° C. within 5 minutes to 70 ml of 0.1N methanolic potassium hydroxide solution
6. additionpoured on to 200 ml of ice-water
7. extractionextracted with diethyl ether
8. washThe ether phases were washed neutral with water
9. dry with materialdried over sodium sulphate
10. concentrationconcentrated