2-Oxobutanoic Acid → Ethyl 3-methylquinoline-2-carboxylate
Reaction equation
[NH2:1][C:2]1[CH:9]=[CH:8][CH:7]=[CH:6][C:3]=1[CH:4]=O.O=[C:11]([CH2:15][CH3:16])[C:12]([OH:14])=[O:13].[O-][CH2:18][CH3:19].[Na+].S(=O)(=O)(O)O.C(=O)(O)[O-].[Na+]>C(O)C>[CH3:16][C:15]1[C:11]([C:12]([O:14][CH2:18][CH3:19])=[O:13])=[N:1][C:2]2[C:3]([CH:4]=1)=[CH:6][CH:7]=[CH:8][CH:9]=2Participants
7
Reactant 5
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
A solution of 2-aminobenzaldehyde, 2-oxobutyric acid (13.5 g, 132 mmol), and sodium ethoxide (13.5 g, 198 mmol) in ethanol (331 mL) was refluxed for 20 h. After being cooled to 0° C., 96% sulfuric acid (10.6 mL, 97.9 mmol) was added. The reaction mixture was refluxed for 20 h. After being cooled to 0° C., the reaction mixture was basified to pH 8-9 with saturated sodium bicarbonate, and the mixture was extracted with chloroform. The organic layer was washed with water and saturated brine, dried over sodium sulfate, filtrated and concentrated in vacuo. The crude was purified by silica gel column chromatography (hexane:ethyl acetate=19:1 to 2:1) to give ethyl 3-methylquinoline-2-carboxylate. MS (APCI): m/z 218 (M+H).
Workup
- temperatureThe reaction mixture was refluxed for 20 h
- temperatureAfter being cooled to 0° C.
- extractionthe mixture was extracted with chloroform
- washThe organic layer was washed with water and saturated brine
- dry with materialdried over sodium sulfate
- filtrationfiltrated
- concentrationconcentrated in vacuo
- customThe crude was purified by silica gel column chromatography (hexane:ethyl acetate=19:1 to 2:1)
Sources & evidence
- ORD record
- ord-fb5ed0eb7cee4d7db377c33d6d61f0f5
- Source dataset
- uspto-grants-2015_03
- Patent number
- US08969376B2
Reaction notes
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