反应详情

When in Example 2, 1-bromo-3,7,11,15-tetramethyhexadecane is substituted for 1-bromohexadecane, 2-(3,7,11,15-tetramethylhexadecyloxy)thiophene is obtained. A solution of 38.1 g (0.1 mole) of 2-(3,7,11,15-tetramethylhexadecyloxy)-thiophene in 50 ml of anhydrous ether is added over a 4 hour period to 6.0 g of sodium amalgam in 100 ml of anhydrous ether at reflux temperature (36°-39° C) under slight nitrogen pressure. The mixture is refluxed an additional 2 hours, then cooled to room temperature are carbonated by adding freshly crushed dry ice after which 20 ml of ethanol is added dropwise followed by the addition of 50 ml of water. The aqueous solution is separated from the ether layer, filtered and acidified with hydrochloric acid to precipitate 5-(3,7,11,15-tetramethylhexadecyloxy)-2-thiophenecarboxylic acid.

1. temperatureat reflux temperature (36°-39° C) under slight nitrogen pressure
2. temperatureThe mixture is refluxed an additional 2 hours
3. additionis added dropwise
4. customThe aqueous solution is separated from the ether layer
5. filtrationfiltered
6. customto precipitate 5-(3,7,11,15-tetramethylhexadecyloxy)-2-thiophenecarboxylic acid