反应详情

A solution of (2-bromoethoxy)-tert-butyldimethylsilane (4.71 g, 19.7 mmol) in tetrahydrofuran (20 ml) was added dropwise at room temperature to a stirred solution of tert-butyl 3-oxopiperazine-1-carboxylate (3.94 g, 19.7 mmol), powdered potassium hydroxide (1.32 g, 23.6 mmol) and tetrabutylammonium bromide (1.27 g, 3.94 mmol) in tetrahydrofuran (30 ml) and the resulting mixture was stirred for 4 hours. The mixture was filtered and then evaporated to leave a colourless viscous oil which was purified by silica gel chromatography eluting with methyl tert-butyl ether as eluent to give tert-butyl 4-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-3-oxopiperazine-1-carboxylate (3.42 g, 45% yield) as a colourless oil:

1. filtrationThe mixture was filtered
2. customevaporated
3. customto leave a colourless viscous oil which
4. customwas purified by silica gel chromatography
5. washeluting with methyl tert-butyl ether as eluent