反应详情

温度

-78 °C

2 g (5.1 mmol) of methyl 6-benzyloxy-5-tert-butyl-4′-methyl-3-biphenylcarboxylate (Example 1,d) are dissolved in 30 mL of THF, 15 mL of methanol and 2 mL of water. 320 mg (7.7 mmol) of lithium hydroxide hydrate are added and the reaction medium is refluxed for 5 hours and then cooled. The medium is neutralized with a 1 N hydrochloric acid solution and the medium is then extracted with ethyl ether. A white powder is obtained (m.p.=196° C.), which is dissolved in 10 mL of ethyl ether and 5 mL of THF. The medium is cooled to −78° C., and 11 mL (11 mmol) of 1 N methyllithium solution are then added dropwise. The medium is stirred at this temperature for 3 hours and is then treated with 5 mL of trimethylsilyl chloride. The medium is hydrolysed with a saturated ammonium chloride solution and then extracted with ethyl ether. The residue obtained is purified by chromatography (eluent: 9 heptane/1 ethyl acetate). A yellow crystalline solid is obtained (m=1.1 g; yield=60%; m.p.=104° C.).

1. temperaturethe reaction medium is refluxed for 5 hours
2. temperaturecooled
3. extractionthe medium is then extracted with ethyl ether
4. customA white powder is obtained (m.p.=196° C.), which
5. extractionextracted with ethyl ether
6. customThe residue obtained
7. customis purified by chromatography (eluent: 9 heptane/1 ethyl acetate)
8. customA yellow crystalline solid is obtained (m=1.1 g; yield=60%; m.p.=104° C.)