反应详情

温度

40 °C

Part A: 2,2'-dihydroxy-5,5'-dimethyoxy-1,1'-biphenyl was prepared by the dealkylation of 2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dimethyoxy-1,1'-biphenyl using a procedure described by Tashiro, M.; Fukata, G., and Yamato, T.; Organic Preparations and Procedures Int., 8, 263 (1976). AlCl3 (10 g) and 10 g of 2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dimethoxy-1,1'-biphenyl were mixed in 125 ml of benzene and heated at 40° C. for 3 h. The mixture was cooled in ice and 125 ml of 10% HCl solution was added slowly. The organic layer was separated and washed with 3×125 ml of 10% NaOH. The basic solution was neutralized with concentrated HCl and extracted with 3×100 ml of ether. The ether layer was dried over Na2SO4. After filtering and removing the solvent by vacuum evaporation, the brown oil was washed with hexane and then the product crystallized from CH2Cl2 /hexane. 2.202 g of 2,2'-dihydroxyl-5,5'-dimethoxy-1,1'-biphenyl was obtained as a white solid. 1H nmr (300 MHz, CD2Cl2): 6.9-6.8 (m, 6H), 5.71 (s, 2H), 3.78 (s, 6H).

1. temperatureThe mixture was cooled in ice
2. customThe organic layer was separated
3. washwashed with 3×125 ml of 10% NaOH
4. extractionextracted with 3×100 ml of ether
5. dry with materialThe ether layer was dried over Na2SO4
6. filtrationAfter filtering
7. customremoving the solvent
8. customby vacuum evaporation
9. washthe brown oil was washed with hexane
10. customthe product crystallized from CH2Cl2 /hexane