Acetaldehyde → (2E)-3-(3,4-dichlorophenyl)prop-2-enal

Temperature

5 °C

A mixture of 3,4-dichlorobenzaldehyde (140.0 g, 0.8 mol) and acetaldehyde (300 mL) was cooled to 5° C. Potassium hydroxide (5.1 g, 0.091 mol) was dissolved in hot MeOH (40 mL), and the resulting solution was added to the above cooled mixture while maintaining the internal temperature at 25° C. to 30° C. The mixture was allowed to stir in ice-H2O bath for 40 minutes and then treated with acetic anhydride (400 mL). After the addition, the mixture was heated to 100° C. with string for 30 minutes and then cooled to 30° C. To this mixture, 12N HCl/H2O (102 mL/1.2 L) was added, and the resulting mixture was heated to reflux for 30 minutes and then cooled to room temperature. This heterogeneous mixture was filtered and washed with H2O to afford a brown solid. The crude product was dissolved in EtOAc and washed with H2O, dried Na2SO4), and concentrated to dryness. Recrystallization from hexane/EtOAc (9:1) yielded 76.5 g (0.38 mol, 48%) of the title compound. mp: 91-93° C.

1. additionthe resulting solution was added to the above cooled mixture
2. temperaturewhile maintaining the internal temperature at 25° C. to 30° C
3. additionAfter the addition
4. temperaturethe mixture was heated to 100° C. with string for 30 minutes
5. temperaturecooled to 30° C
6. temperaturethe resulting mixture was heated
7. temperatureto reflux for 30 minutes
8. temperaturecooled to room temperature
9. filtrationThis heterogeneous mixture was filtered
10. washwashed with H2O
11. customto afford a brown solid
12. washwashed with H2O, dried Na2SO4), and
13. concentrationconcentrated to dryness
14. customRecrystallization from hexane/EtOAc (9:1)

ORD record

ord-eb3b6fc8f04244a3b0817c8200849d62

Source dataset

uspto-grants-2005_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06972287B1