반응 #68752

반응 방정식

5-bromo-2-trifluoromethoxybenzaldehyde

boron trifluoride etherate

water

boron trifluoride etherate

1,2-bis(trimethylsiloxy)cyclobutene

→

2-(5-bromo-2-trifluoromethoxyphenyl)cyclopentane-1,3-dione

용매

dichloromethane

반응 조건

후처리

1. 1
   workup.STIRRINGAfter stirring for 24 hours at room temperature the reaction mixture
2. 2
   기타is then quenched with saturated aqueous ammonium chloride solution (50 ml)
3. 3
   추출extracted with dichloromethane (2×50 ml)
4. 4
   추출The crude product is extracted from the organic phase
5. 5
   세척by washing with 0.5 M aqueous potassium carbonate solution (×3)
6. 6
   추출Final extraction with dichloromethane (×3)
7. 7
   세척by washing with brine
8. 8
   건조then drying over magnesium sulfate and filtration
9. 9
   농축Concentration in vacuo
10. 10
    기타gives a crude product which
11. 11
    기타is purified by preparative reverse phase HPLC

실험 절차

To a solution of 5-bromo-2-trifluoromethoxybenzaldehyde (2.0 g, 7.43 mmol) in anhydrous dichloromethane (40 ml) at room temperature is added boron trifluoride etherate (1.13 ml, 8.92 mmol) then 1,2-bis(trimethylsiloxy)cyclobutene (2.86 ml, 11.2 mmol). The mixture is stirred at room temperature for 23 hours, followed by addition of distilled water (1.2 ml) and additional boron trifluoride etherate (14.1 ml, 112 mmol). After stirring for 24 hours at room temperature the reaction mixture is then quenched with saturated aqueous ammonium chloride solution (50 ml) and extracted with dichloromethane (2×50 ml). The crude product is extracted from the organic phase by washing with 0.5 M aqueous potassium carbonate solution (×3), then acidified to pH 1 with concentrated hydrochloric acid. Final extraction with dichloromethane (×3) is followed by washing with brine then drying over magnesium sulfate and filtration. Concentration in vacuo gives a crude product which is purified by preparative reverse phase HPLC to afford 2-(5-bromo-2-trifluoromethoxyphenyl)cyclopentane-1,3-dione.

출처