Sulfuric Acid → 2-(3,4-Dihydroxybenzylcarbamoyl)-8-hydroxyquinoline-7-carboxylic acid
Reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([CH:33]=[CH:34][C:35]=1[OH:36])[CH2:5][NH:6][C:7]([C:9]1[CH:18]=[CH:17][C:16]2[C:11](=[C:12]([O:26]C(=O)C(C)(C)C)[C:13]([C:19]([O:21]CCCC)=[O:20])=[CH:14][CH:15]=2)[N:10]=1)=[O:8].[OH-].[Na+].S(=O)(=O)(O)O>CO>[OH:1][C:2]1[CH:3]=[C:4]([CH:33]=[CH:34][C:35]=1[OH:36])[CH2:5][NH:6][C:7]([C:9]1[CH:18]=[CH:17][C:16]2[C:11](=[C:12]([OH:26])[C:13]([C:19]([OH:21])=[O:20])=[CH:14][CH:15]=2)[N:10]=1)=[O:8]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 20 °C
Procedure
A mixture of the preceding amide 7 (step 6) (0.5 g, 1.0 mmol) and 6.5 ml of a 3 N sodium hydroxide solution in 10 ml of methanol is stirred at 20° C. for 3 hours. The pH is adjusted to 4 with 1 N sulfuric acid solution. The reaction mixture is concentrated under reduced pressure, and then dried under vacuum over phosphoric anhydride. The residue is taken up in 10 ml of anhydrous ethanol in the hot state and the insoluble sodium sulfate is filtered. The filtrate is concentrated under reduced pressure and then taken up in 2 ml of anhydrous ethanol. The medium is cooled: a yellowish solid crystallizes. The latter is washed with dichloromethane, and then dried under vacuum over phosphoric anhydride so as to give 250 mg of acid 8 in the form of a brown solid.
Workup
- concentrationThe reaction mixture is concentrated under reduced pressure
- dry with materialdried under vacuum over phosphoric anhydride
- filtrationthe insoluble sodium sulfate is filtered
- concentrationThe filtrate is concentrated under reduced pressure
- temperatureThe medium is cooled
- customa yellowish solid crystallizes
- washThe latter is washed with dichloromethane
- dry with materialdried under vacuum over phosphoric anhydride so as
Sources & evidence
- ORD record
- ord-4c7429a3ee514feda0e617f88d45ee81
- Source dataset
- uspto-grants-2006_06
- Patent number
- US07064133B2
Reaction notes
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