4-Hydroxybenzaldehyde → Methyl 5-(4-hydroxyphenyl)-3-oxo-4-pentenoate
Reaction equation
[C:1]([O:7][CH3:8])(=[O:6])[CH2:2][C:3]([CH3:5])=[O:4].[OH:9][C:10]1[CH:17]=[CH:16][C:13]([CH:14]=O)=[CH:12][CH:11]=1.C(O)(=O)C.N1CCCCC1>CC1CCCCC1.O>[OH:9][C:10]1[CH:17]=[CH:16][C:13]([CH:14]=[CH:5][C:3](=[O:4])[CH2:2][C:1]([O:7][CH3:8])=[O:6])=[CH:12][CH:11]=1Participants
Procedure
##STR7## 232 g (2 mol) of methyl acetoacetate, 244 g (2 mol) of 4-hydroxybenzaldehyde, 24 g (0.4 mol) of glacial acetic acid and 6.8 g (0.08 mol) of piperidine were dissolved in 459 ml of methylcyclohexane. The reaction solution was heated to the boil, and the water of reaction was separated off for one hour in a water separator. After the solvent had been decanted, the product was taken up in diethyl ether, filtered off with suction and dried. 362 g (corresponding to a yield of 82%) of methyl 4-hydroxybenzalacetoacetate were obtained. 22 g (0.1 mol) of methyl 4-hydroxybenzalacetoacetate were dissolved in 100 ml of methanol, and 5.6 g (0.1 mol) of KOH in 38 g of methanol were added. Stirring was carried out for 2.5 hours at room temperature, after which the reaction mixture was evaporated down and the remaining residue was dried. 25 g (corresponding to a yield of 97% of the title compound were obtained in the form of a red solid. The purity of the product was >95%.
Workup
- temperatureThe reaction solution was heated to the boil
- customwas separated off for one hour in a water separator
- customAfter the solvent had been decanted
- filtrationfiltered off with suction
- customdried
Sources & evidence
- ORD record
- ord-3cb19a1ef8264411b709ac6b9256a86b
- Source dataset
- uspto-grants-1999_09
- Patent number
- US05951841
Reaction notes
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