反应详情

温度

-78 °C

3-Bromophenoxy-tert-butyldimethylsilane (57.5 g, 0.20 mol, Example 1, infra) was dissolved in 300 mL of dry tetrahydrofuran under nitrogen and cooled to -78° C. A solution of 1.6M n-butyllithium in hexane (125 mL, 0.20 mol) was added dropwise at a rate to maintain a temperature below -70° C. The reaction was stirred for thirty minutes after the addition was complete and the cold solution was transferred to another vessel containing a -40° C. solution of magnesium bromide (37.8 g, 0.205 mol) in 600 mL of dry tetrahydrofuran under nitrogen. The resulting solution was allowed to warm to -15° C. while stirring. After one hour a solution of thiophene-3-carboxaldehyde (22.4 g, 0.20 mol) in 200 mL of dry tetrahydrofuran was added slowly at a rate to maintain a temperature below 25° C. The resulting solution was stirred for 30 minutes at room temperature, then washed twice with aqueous ammonium chloride, dried over sodium sulfate and evaporated to give a brown oil. Chromatography on silica gel with hexane:dichloromethane (gradient from 3:1 to 1:1) gave 44.1 g (69%) of 3-((tert-butyldimethylsilyl)oxy)-α-(3-thienyl)benzyl alcohol as a viscous yellow oil.

1. temperatureto maintain a temperature below -70° C
2. additionafter the addition
3. customthe cold solution was transferred to another vessel
4. temperatureto warm to -15° C.
5. stirringwhile stirring
6. temperatureto maintain a temperature below 25° C
7. stirringThe resulting solution was stirred for 30 minutes at room temperature
8. washwashed twice with aqueous ammonium chloride
9. dry with materialdried over sodium sulfate
10. customevaporated
11. customto give a brown oil