反应详情

温度

155 °C

0.4 g of copper-I bromide and 43.5 g (0.375 mole) of sodium phenolate were added to 95 ml of diethylene glycol dimethyl ether (diglyme). The temperature of the mixture rose to about 80° C. To effect dehydration, 15 ml of diglyme (boiling point 160° C.) were distilled off under normal pressure. 57.3 g (0.23 mole) of 3-bromo-4-fluoro-benzaldehyde dimethyl acetal were then added dropwise in the course of 10 minutes, at 150°-155° C., and the reaction mixture was stirred for a further 7 hours at 155° C. Gas chromatography indicated that all of the precursor had then been converted. Subsequently, the solvent was distilled off at 40° C./10 mm Hg, the residue was dissolved in 300 ml of toluene and, after adding 10 g of "Celite" (Trade Mark) 545 as a filter aid, the mixture was filtered to remove the inorganic material. The filtrate was washed with twice 100 ml of 50% strength sodium hydroxide solution, the solvent was then stripped off in vacuo and the residue was distilled in vacuo. 45.5 g (75. of theory) of 3-phenoxy-4-fluoro-benzaldehyde dimethyl acetal were thus obtained in the form of a colorless oil with a boiling point of 128°-130° C./0.1 mm Hg.

1. customrose to about 80° C
2. distillationTo effect dehydration, 15 ml of diglyme (boiling point 160° C.) were distilled off under normal pressure
3. distillationSubsequently, the solvent was distilled off at 40° C./10 mm Hg
4. dissolutionthe residue was dissolved in 300 ml of toluene
5. additionafter adding 10 g of "Celite" (Trade Mark) 545 as a filter aid
6. filtrationthe mixture was filtered
7. customto remove the inorganic material
8. washThe filtrate was washed with twice 100 ml of 50% strength sodium hydroxide solution
9. distillationthe residue was distilled in vacuo