反应详情

温度

0 °C

18.9 ml (30.30 mmol) of 1.6M n-BuLi solution in n-hexane are added dropwise at 0° C. to 4.50 g (12.10 mmol) of 5-bromo-3-chloro-2-(4-octyloxyphenyl)pyridine and 2.7 ml (24.20 mmol) of trimethyl borate in 70 ml of tetrahydrofuran, and the mixture is stirred at 0° C. for 0.5 hour. The mixture is subsequently acidified by means of dilute hydrochloric acid and partitioned between aqueous sodium chloride solution and ether, the organic phase is washed with sodium chloride solution, dried over sodium sulfate and filtered, and the filtrate is evaporated. The dry residue is dissolved in 100 ml of tetrahydrofuran and refluxed for 2 hours with 5 ml of 35% strength hydrogen peroxide. After the mixture has been cooled to 0° C., 6.3 g of Na2SO3 in 45 ml of water are added dropwise, and the mixture is stirred at room temperature for a quarter of an hour. The mixture is subsequently partitioned between ether and aqueous sodium chloride solution, the organic phase is washed with sodium chloride solution, dried over sodium sulfate and filtered, and the filtrate is evaporated to dryness. Chromatographic purification (silica gel, dichloromethane:ethyl acetate=4:1) gives 2.35 g of 3-chloro-5-hydroxy-2-(4-octyloxyphenyl)pyridine. ##STR18## m.p.: 128°-129.5° C.

1. custompartitioned between aqueous sodium chloride solution and ether
2. washthe organic phase is washed with sodium chloride solution
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. customthe filtrate is evaporated
6. dissolutionThe dry residue is dissolved in 100 ml of tetrahydrofuran
7. temperaturerefluxed for 2 hours with 5 ml of 35% strength hydrogen peroxide
8. temperatureAfter the mixture has been cooled to 0° C.
9. addition6.3 g of Na2SO3 in 45 ml of water are added dropwise
10. stirringthe mixture is stirred at room temperature for a quarter of an hour
11. customThe mixture is subsequently partitioned between ether and aqueous sodium chloride solution
12. washthe organic phase is washed with sodium chloride solution
13. dry with materialdried over sodium sulfate
14. filtrationfiltered
15. customthe filtrate is evaporated to dryness
16. customChromatographic purification (silica gel, dichloromethane:ethyl acetate=4:1)