반응 #501486

반응 방정식

3-bromo-4-fluorobenzaldehyde

ethylene glycol

→

2-(3-bromo-4-fluorophenyl)-1,3-dioxolane

수율 78.3%

용매

toluene

반응 조건

후처리

1. 1
   온도was heated at the reflux temperature under a Dean and Stark trap
2. 2
   기타approximately 12 cm3 of water had collected in the trap, and analysis of the reaction mixture by gas liquid chromatography
3. 3
   온도The mixture was cooled
4. 4
   workup.ADDITIONpoured into diethyl ether
5. 5
   세척washed with saturated sodium bicarbonate solution and brine
6. 6
   건조dried over anhydrous magnesium sulphate
7. 7
   기타Evaporation of the solvent under reduced pressure
8. 8
   기타gave a yellow oil, which
9. 9
   workup.DISTILLATIONwas purified by distillation under reduced pressure

실험 절차

A mixture of 3-bromo-4-fluorobenzaldehyde (45.7 g), ethylene glycol (27.93 g), p-toluenesulphonic acid (0.225 g) and dry toluene (110 cm3) was heated at the reflux temperature under a Dean and Stark trap. After 4.5 hours, approximately 12 cm3 of water had collected in the trap, and analysis of the reaction mixture by gas liquid chromatography indicated that no starting aldehyde was present. The mixture was cooled and poured into diethyl ether, washed with saturated sodium bicarbonate solution and brine, and dried over anhydrous magnesium sulphate. Evaporation of the solvent under reduced pressure gave a yellow oil, which was purified by distillation under reduced pressure to give 2-(3-bromo-4-fluorophenyl)-1,3-dioxolane (43.56 g), boiling point 68°-106° C. at 0.004 mmHg.

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