Potassium Hydroxide → 4-(2',5'-Dimethoxy-3',4',6'-trimethylphenyl)-2-keto-3-butenoic acid
Reaction equation
[CH3:1][O:2][C:3]1[C:10]([CH3:11])=[C:9]([CH3:12])[C:8]([O:13][CH3:14])=[C:7]([CH3:15])[C:4]=1[CH:5]=O.[C:16]([O-:21])(=[O:20])[C:17]([CH3:19])=[O:18].[Na+].[OH-].[K+]>CO>[CH3:1][O:2][C:3]1[C:10]([CH3:11])=[C:9]([CH3:12])[C:8]([O:13][CH3:14])=[C:7]([CH3:15])[C:4]=1[CH:5]=[CH:19][C:17](=[O:18])[C:16]([OH:21])=[O:20]Participants
Procedure
A suspension of 3.7 g (17.6 mmol) of 2,5-dimethoxy-3,4,6-trimethylbenzaldehyde and 5.0 g (53.2 mmol) of sodium pyruvate in 20 ml of methanol is treated with 0.1 g (1.8 mmol) of potassium hydroxide and the mixture is subsequently heated at reflux for 5 hours, whereby a yellow solution is obtained. The reaction mixture is poured on to ice-water and the resulting 4-(2',5'-dimethoxy-3',4',6'-trimethyphenyl)-2-keto-3-butenoic acid is precipitated by the addition of sulphuric acid while stirring. The suspension is stirred for 1 hour, filtered, the filter residue is washed with water and dried. In this manner there are obtained 4.9 g of 4-(2',5'-dimethoxy-3',4',6'-trimethylphenyl)-2-keto-3-butenoic acid in the form of a yellow powder of melting point 126°-127° C.
Workup
- temperaturethe mixture is subsequently heated
- temperatureat reflux for 5 hours
- customwhereby a yellow solution is obtained
- customthe resulting 4-(2',5'-dimethoxy-3',4',6'-trimethyphenyl)-2-keto-3-butenoic acid is precipitated by the addition of sulphuric acid
- stirringThe suspension is stirred for 1 hour
- filtrationfiltered
- washthe filter residue is washed with water
- customdried
Sources & evidence
- ORD record
- ord-d54bca8796204ec988f13eb0cdcfad53
- Source dataset
- uspto-grants-1989_04
- Patent number
- US04824972
Reaction notes
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