反应详情

Under a blanket of nitrogen, 8.2 g (0.172 moles) 50% sodium hydride was washed with hexane. The flask was charged with 250 ml dry N,N-dimethylformamide and 11.5 g (0.086 moles) 2,2'-bi-1H-imidazole was added in small portions. After stirring at room temperature for 11/2 hours 30.8 g (0.185 moles) 2-(trimethylsilyl)ethoxymethyl chloride (SEM-Cl) was added dropwise. The reaction exothermed slightly. The reaction was stirred for 1 hour then quenched with water and extracted into ethyl acetate (3×200 ml). The combined organic layers were shaken with water (2×300 ml), dried (anhydrous sodium sulfate) and concentrated to give 33.4 g tan oil. The product was purified by preparative HPLC (ethyl acetate) to give 26.9 g (79.2%) desired product as a light tan oil. A small portion was distilled. bp 260° C. at 0.2 mm.

1. additionwas added in small portions
2. additionwas added dropwise
3. customthen quenched with water
4. extractionextracted into ethyl acetate (3×200 ml)
5. stirringThe combined organic layers were shaken with water (2×300 ml)
6. dry with materialdried (anhydrous sodium sulfate)
7. concentrationconcentrated