反应详情

4-Bromo-4'-hydroxybiphenyl (2.49 g) was added over 30 minutes to a stirred suspension of sodium hydride (0.42 g of 60% dispersion in mineral oil) in dimethylformamide (10 ml) whilst keeping the temperature of the reaction mixture below 10° C. The reaction mixture was stirred at a temperature below 10° C. for a futher 5 minutes. Ethyl iodide (1.87 g) was added over 10 minutes and stirring continued at room temperature for 2 hours. Water (200 ml) was added to the mixture and the mixture extracted with diethyl ether (3×50 ml). The ether extracts were combined, washed with 1M sodium hydroxide solution (50 ml) and brine (50 ml), dried (MgSO4) and evaporated to give a residue which was crystallised from hexane to give, as a colourless solid, 4-bromo-4'-ethoxybiphenyl (2.15 g), m.p. 139° C.; NMR (CDCl3): 1.4(3H, t), 4.0-4.1(2H, q), 6.9(2H, d) and 7.35-7.55(6H, m).

1. customthe temperature of the reaction mixture below 10° C
2. stirringstirring
3. waitcontinued at room temperature for 2 hours
4. extractionthe mixture extracted with diethyl ether (3×50 ml)
5. washwashed with 1M sodium hydroxide solution (50 ml) and brine (50 ml)
6. dry with materialdried (MgSO4)
7. customevaporated
8. customto give a residue which
9. customwas crystallised from hexane