Hydrochloric Acid → 4-Hydroxy-7-methoxy-8-methyl-quinoline
Reaction equation
[OH:1][C:2]1[C:11]2[C:6](=[C:7]([CH3:14])[C:8]([O:12][CH3:13])=[CH:9][CH:10]=2)[N:5]=[CH:4][C:3]=1C(OCC)=O.Cl>[OH-].[Na+]>[OH:1][C:2]1[C:11]2[C:6](=[C:7]([CH3:14])[C:8]([O:12][CH3:13])=[CH:9][CH:10]=2)[N:5]=[CH:4][CH:3]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
A suspension of ethyl 4-hydroxy-7-methoxy-8-methylquinoline-3-carboxylate (58, 9.2 g, 35.2 mmol) in 5N NaOH (150 mL) was refluxed for 1.5 h (until a clear solution was obtained). Then, the solution was cooled to 0° C. and the pH adjusted to 2-3 with concentrated HCl. The solid was filtered off and successively washed with water, acetone and ether. This powder was added in small portions to diphenylether (40 mL), pre-heated at 250° C. The resulting suspension became a solution after 20 min (CO2 formation was observed). After 1 h at 250° C., the brown solution was cooled to room temperature and diluted with heptanes (200 mL). The precipitate was filtered off and washed with heptanes and ether to give 6.4 g (96%) of the target product 59 as a yellow powder: m/z=190 (M+H)+.
Workup
- temperaturewas refluxed for 1.5 h (until a clear solution
- customwas obtained)
- filtrationThe solid was filtered off
- washsuccessively washed with water, acetone and ether
- additionThis powder was added in small portions to diphenylether (40 mL)
- temperaturepre-heated at 250° C
- customafter 20 min
- temperaturethe brown solution was cooled to room temperature
- additiondiluted with heptanes (200 mL)
- filtrationThe precipitate was filtered off
- washwashed with heptanes and ether
Sources & evidence
- ORD record
- ord-ff15985744a5435da79e56a9785f107d
- Source dataset
- uspto-grants-2012_04
- Patent number
- US08153800B2
Reaction notes
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