反应详情

tert-butyl(2-(5-chlorothiophen-2-yl)ethoxy)dimethylsilane (0.8 g) (example 278, step a) was added dropwise over 5 min to a stirred solution of butyl lithium (2.5M in hexanes 1.7 mL) and 2,2,6,6-tetramethylpiperidine (0.73 mL) in THF (25 mL) at −78° C. The resulting mixture was stirred for 2 hrs and DMF (0.67 mL) was added. The mixture was stirred for a further 1 hr and allowed to warm to RT. The reaction was cautiously poured into HCl solution (0.5M, 200 mL) and extracted with ethyl acetate (3×100 mL). The combined organic solutions were washed with water (2×100 mL), brine (100 mL), dried over sodium sulphate, filtered and evaporated in vacuo. The resulting oil was purified by silica gel chromatography eluting with iso-hexane to 5% ether in iso-hexane gradient. The fractions containing product were combined and evaporated in vacuo to give the subtitle compound as a clear oil. Yield (0.8 g)

1. stirringThe mixture was stirred for a further 1 hr
2. extractionextracted with ethyl acetate (3×100 mL)
3. washThe combined organic solutions were washed with water (2×100 mL), brine (100 mL)
4. dry with materialdried over sodium sulphate
5. filtrationfiltered
6. customevaporated in vacuo
7. customThe resulting oil was purified by silica gel chromatography
8. washeluting with iso-hexane to 5% ether in iso-hexane gradient
9. additionThe fractions containing product
10. customevaporated in vacuo