Propanal → (2E)-2-Methyl-3-(3-methylphenyl)-2-propenal
Reaction equation
[OH-].[K+].O.[CH3:4][C:5]1[CH:6]=[C:7]([CH:10]=[CH:11][CH:12]=1)[CH:8]=O.[CH:13](=[O:16])[CH2:14][CH3:15]>C(O)CO>[CH3:15]/[C:14](=[CH:8]\[C:7]1[CH:10]=[CH:11][CH:12]=[C:5]([CH3:4])[CH:6]=1)/[CH:13]=[O:16]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 40 °C
Procedure
A solution of potassium hydroxide (24 g, 0.36 mol, 0.6 eq, with a purity of 85%) in ethylene glycol (120 g) and water (12 g) was charged into a 500 mL three-necked round-bottom flask equipped with a reflux condenser and a mechanical stirrer. 3-methyl benzaldehyde (70 g, 0.59 mol) was added dropwise. The stirred reaction mixture was heated at 38-42° C. and propionaldehyde (41 g, 0.71 mol, 1.2 eq) was dosed in over 3.25 h. After a further hour at 40° C., the reaction mixture was cooled to ambient temperature and the two layers separated. The organic layer thus obtained was washed with water (2×100 mL), dried over magnesium sulphate and concentrated. The resulting crude product was distilled via a Vigreux column (1.0 mBar, 87-92° C.), to give (2E)-2-methyl-3-(3-methylphenyl)acrylaldehyde (65.9 g, gc purity>95%; yield 70%).
Workup
- customequipped with a reflux condenser and a mechanical stirrer
- customThe stirred reaction mixture
- customwas dosed in over 3.25 h
- waitAfter a further hour at 40° C.
- temperaturethe reaction mixture was cooled to ambient temperature
- customthe two layers separated
- customThe organic layer thus obtained
- washwas washed with water (2×100 mL)
- dry with materialdried over magnesium sulphate
- concentrationconcentrated
- distillationThe resulting crude product was distilled via a Vigreux column (1.0 mBar, 87-92° C.)
Sources & evidence
- ORD record
- ord-7d5d6fe7d1724e9483a2d243a78968a6
- Source dataset
- uspto-grants-2014_04
- Patent number
- US08709994B2
Reaction notes
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