反应详情

Gaseous hydrogen chloride was passed into a cold (5° to 10°), rapidly stirred solution of 240 ml (1.96 m) p-xylene and 54.75 ml (0.98 m) acetaldehyde (I) until the conversion (monitored by means of nuclear magnetic resonance spectroscopy) of aldehyde I to bis-1-chloroethyl ether (II) was complete. The lower, aqueous phase was removed and 20 ml (1.96 m) p-xylene (III) and dichloromethane (55 ml) were added. The reaction mixture was cooled and maintained in the temperature range 0° to 5° while the introduction of hydrogen chloride and rapid stirring were continued. Concentrated sulfuric acid, 54.75 ml (1.03 m), was added during 55 minutes. After the addition was completed, stirring and cooling were continued for 45 minutes. The reaction mixture was then quenched with 200 ml water. The resulting mixture was neutralized with concentrated ammonium hydroxide and the organic phase was collected. Dichloromethane (40 ml) was distilled from the organic phase at atmospheric pressure. Fractional distillation of the remainder of the product mixture at reduced pressure (about 30 mm Hg) afforded 333.3 g (3.14 m) xylene III and 78.2 g (0.47 m) chloride IV. The isolated yield of chloride IV was 48% based on aldehyde I or 60% based on consumed xylene III.

1. customThe lower, aqueous phase was removed
2. addition20 ml (1.96 m) p-xylene (III) and dichloromethane (55 ml) were added
3. temperatureThe reaction mixture was cooled
4. temperaturemaintained in the temperature
5. customrange 0° to 5° while the introduction of hydrogen chloride
6. additionConcentrated sulfuric acid, 54.75 ml (1.03 m), was added during 55 minutes
7. additionAfter the addition
8. stirringstirring
9. temperaturecooling
10. customThe reaction mixture was then quenched with 200 ml water
11. customthe organic phase was collected
12. distillationDichloromethane (40 ml) was distilled from the organic phase at atmospheric pressure
13. distillationFractional distillation of the remainder of the product mixture at reduced pressure (about 30 mm Hg)