Boron Trichloride → 2-Formyl-3-hydroxy-5-methoxy-6-methylbenzoic acid methyl ester
Reaction equation
[CH3:1][O:2][C:3](=[O:17])[C:4]1[C:9]([CH3:10])=[C:8]([O:11][CH3:12])[CH:7]=[C:6]([O:13]C)[C:5]=1[CH:15]=[O:16].B(Cl)(Cl)Cl>ClCCl>[CH3:1][O:2][C:3](=[O:17])[C:4]1[C:9]([CH3:10])=[C:8]([O:11][CH3:12])[CH:7]=[C:6]([OH:13])[C:5]=1[CH:15]=[O:16]Participants
Conditions
- Temperature
- 20 °C
Procedure
To a suspension of 95.3 g of 2-formyl-3,5-dimethoxy-6-methylbenzoic acid methyl ester in 250 ml of dichloromethane were added 800 ml of a 1M solution of boron trichloride in dichloromethane over 40 min at a temperature of 5°-10° C. The mixture was allowed to warm to 20° C. within 30 min and stirring was continued at room temperature for 4 h. The clear solution was cooled to 5° C. and then poured into a mixture of 1.5 l of ice-water and 0.5 l of dichloromethane. The layers were separated and the aqueous phase was back-extracted with 0.4 l of dichloromethane. The organic layers were washed with water, dried over sodium sulfate and evaporated in vacuo. Crystallization of the residual material from ethyl acetate/hexane provided 77.3 g of 2-formyl-3-hydroxy-5-methoxy-6-methylbenzoic acid methyl ester as colorless crystals of m.p. 118°-119° C.
Workup
- temperatureThe clear solution was cooled to 5° C.
- customThe layers were separated
- extractionthe aqueous phase was back-extracted with 0.4 l of dichloromethane
- washThe organic layers were washed with water
- dry with materialdried over sodium sulfate
- customevaporated in vacuo
- customCrystallization of the residual material from ethyl acetate/hexane
Sources & evidence
- ORD record
- ord-268c6b77c2eb41cbba6a870f74f510b4
- Source dataset
- uspto-grants-1996_12
- Patent number
- US05589473
Reaction notes
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