反应详情

温度

0 °C

Dry dimethylformamide (20 ml) was added dropwise to a stirred solution of phosphorus oxychloride (18 ml) maintained at a remperature of 0° C. The reaction mixture was allowed to warm to room temperature and p-methoxyphenoxyacetaldehyde diethyl acetal (16 g) was added with stirring. The mixture was cautiously heated with stirring to a temperature of 90° C. and then maintained at that temperature for 6 hr. The mixture was then cooled and poured slowly onto crushed ice (c. 1 kg) and the pH of the solution adjusted to pH10 by the addition, with stirring, of solid potassium carbonate. A benzene (95%)/alcohol (5%) solution (500 ml) was added to the reaction mixture and the total mixture heated just below its boiling point for 2 hr. The mixture was cooled, the organic layer was separated and dried, and the solvent removed by distillation under reduced pressure to give a black oil. The product crystallised from ethanol, after treatment with charcoal, to give 2-(p-methoxyphenoxy)-3-(dimethylamino)-acrolein (6.4 g) which was characterised by p.m.r. spectroscopy.

1. temperatureto warm to room temperature
2. temperatureThe mixture was cautiously heated
3. stirringwith stirring to a temperature of 90° C.
4. temperaturemaintained at that temperature for 6 hr
5. temperatureThe mixture was then cooled
6. additionpoured slowly
7. temperaturethe total mixture heated just below its boiling point for 2 hr
8. temperatureThe mixture was cooled
9. customthe organic layer was separated
10. customdried
11. customthe solvent removed by distillation under reduced pressure
12. customto give a black oil
13. customThe product crystallised from ethanol