反应详情

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

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