반응 #69984

반응 방정식

2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl

sodium tert-butoxide

4-(5-bromopyridin-2-yl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester

4-(benzyloxycarbonyl)piperazine

→

4-[5-(4-(benzyloxycarbonyl)piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester

수율 74.1%

용매

Ethyl acetate

toluene

반응 조건

후처리

1. 1
   세척the mixture is washed once with water and once with a saturated aqueous sodium chloride solution
2. 2
   건조The organic phase is dried over magnesium sulphate
3. 3
   농축concentrated under reduced pressure
4. 4
   기타The crude product obtained
5. 5
   기타is chromatographed on silica gel, elution
6. 6
   workup.ADDITIONbeing carried out with a gradient of a mixture of heptane/ethyl acetate (90/10 to 0/100)

실험 절차

10.12 g of 4-(5-bromopyridin-2-yl)-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester and 5.7 g of 4-(benzyloxycarbonyl)piperazine are placed in 118 ml of toluene and then 0.95 g of tris(dibenzylideneacetone)dipalladium(0), 1.7 g of 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl and 3.5 g of sodium tert-butoxide are added. The reaction medium is heated at 110° C. for 3 h. Ethyl acetate is subsequently added and the mixture is washed once with water and once with a saturated aqueous sodium chloride solution. The organic phase is dried over magnesium sulphate and concentrated under reduced pressure. The crude product obtained is chromatographed on silica gel, elution being carried out with a gradient of a mixture of heptane/ethyl acetate (90/10 to 0/100). 10.16 g of 4-[5-(4-(benzyloxycarbonyl)piperazin-1-yl)pyridin-2-yl]-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester are obtained.

출처