반응 #57094

반응 방정식

3,4-dichlorophenyl boronic acid

sodium carbonate

tert-butyl 4-[2-(3-bromophenyl)-2-(1-hydroxycyclohexyl)ethyl]piperazine-1-carboxylate

→

tert-butyl 4-[2-(3′,4′-dichloro-biphenyl-3-yl)-2-(1-hydroxycyclohexyl)ethyl]piperazine-1-carboxylate

수율 67.0%

용매

1,2-dimethoxyethane

반응 조건

후처리

1. 1
   온도at reflux until all starting material
2. 2
   기타was consumed
3. 3
   기타precipitation of black palladium
4. 4
   기타(3 h)
5. 5
   온도After cooling
6. 6
   workup.ADDITIONwater was added
7. 7
   추출the reaction mixture was extracted with ethyl acetate (30 mL)
8. 8
   세척The organic layer was washed with brine
9. 9
   건조dried over sodium sulfate
10. 10
    여과filtered
11. 11
    농축concentrated
12. 12
    기타to give a crude solid, which
13. 13
    기타was purified via flash column chromatography (silica, gradient from 0% ethyl acetate/hexane to 30% ethyl acetate/hexane)

실험 절차

A mixture of tert-butyl 4-[2-(3-bromophenyl)-2-(1-hydroxycyclohexyl)ethyl]piperazine-1-carboxylate (0.72 g, 1.55 mmol) and tetrakis(triphenylphosphine)palladium (37 mg, 0.032 mmol, 10 mol %) in 1,2-dimethoxyethane (30 mL) was stirred for 10 min at room temperature. To this mixture was added sequentially 3,4-dichlorophenyl boronic acid (0.44 g, 2.32 mmol) and a 2M aqueous solution of sodium carbonate (0.8 mL, 1.6 mmol, 5 equivalent), and the mixture was heated at reflux until all starting material was consumed and precipitation of black palladium occurred (3 h). After cooling, water was added and the reaction mixture was extracted with ethyl acetate (30 mL). The organic layer was washed with brine, dried over sodium sulfate, filtered and concentrated to give a crude solid, which was purified via flash column chromatography (silica, gradient from 0% ethyl acetate/hexane to 30% ethyl acetate/hexane) to yield 0.55 g (67%) of tert-butyl 4-[2-(3′,4′-dichloro-biphenyl-3-yl)-2-(1-hydroxycyclohexyl)ethyl]piperazine-1-carboxylate as a foam, which was used as such in the next step.

출처