反应详情

A solution of 20 g of 1-ethoxycarbonylpiperazine in 400 ml dry tetrahydrofuran is cooled to -65° and 61.5 ml of 2.1M solution of n-butyllithium in hexane is added dropwise over a period of 15 minutes. The mixture is stirred for 15 minutes and a solution of 16.44 ml of chlorotrimethylsilane in 68 ml of tetrahydrofuran is added dropwise over a period of 15 minutes. The mixture is then allowed to warm up to room temperature overnight and evaporated to dryness. Ethyl ether is added, the solids are filtered off, the filtrate is evaporated to dryness and the residue is distilled to give 1-ethoxycarbonyl-4-trimethylsilylpiperazine, b.p. 102°-107°/0.1 mm/Hg.

1. customevaporated to dryness
2. additionEthyl ether is added
3. filtrationthe solids are filtered off
4. customthe filtrate is evaporated to dryness
5. distillationthe residue is distilled