Potassium Carbonate → Methyl 5-methyl-1-benzofuran-2-carboxylate
Reaction equation
[CH3:1][C:2]1[CH:9]=[C:6]([CH:7]=O)[C:5]([OH:10])=[CH:4][CH:3]=1.C([O-])([O-])=O.[K+].[K+].[CH3:17][O:18][C:19](=[O:26])[CH:20](Br)C(OC)=O>[N+](CCCC)(CCCC)(CCCC)CCCC.[Br-].C1(C)C=CC=CC=1>[CH3:17][O:18][C:19]([C:20]1[O:10][C:5]2[CH:4]=[CH:3][C:2]([CH3:1])=[CH:9][C:6]=2[CH:7]=1)=[O:26]Participants
6
Conditions
- Temperature
- 25 °C
Procedure
A stirring suspension of 5methylsalicylaldehyde (1.0 mg, 7.5 mmol), K2CO3 (1.55 g, 11.0 mmol), and Bu4NBr (322 mg, 1 mmol) in toluene (30 ml) was treated with dimethylbromomalo-nate (1.06 ml, 8.0 mmol). The suspension was heated to reflux with a Dean-Stark trap for 20 h. The brown suspension was cooled to 25° C. and concentrated in vacuo. The residue was taken in DCM and filtered. The filtrate was washed with H2O, 1N NaOH and brine. The organic layer was dried over magnesium sulfate, filtered and concentrated. The crude residue was purified by column chromatography (10% ethyl acetate/hexane) to afford the title compound 583 (600 mg, 42% yield). LRMS: 190.2 (Calc.). 191.1 (found).
Workup
- temperatureThe suspension was heated
- temperatureto reflux with a Dean-Stark trap for 20 h
- concentrationconcentrated in vacuo
- filtrationfiltered
- washThe filtrate was washed with H2O, 1N NaOH and brine
- dry with materialThe organic layer was dried over magnesium sulfate
- filtrationfiltered
- concentrationconcentrated
- customThe crude residue was purified by column chromatography (10% ethyl acetate/hexane)
Sources & evidence
- ORD record
- ord-536b475f604d4a9880881b7a8e4b0457
- Source dataset
- uspto-grants-2005_05
- Patent number
- US06897220B2
Reaction notes
Loading…