Methanol → 5H-Indeno[1,2-b]pyridine-5-carboxylic acid, 5-hydroxy-, methyl ester
Reaction equation
[Na].[OH:2][C:3]1([C:16]([OH:18])=[O:17])[C:15]2[C:10](=[N:11][CH:12]=[CH:13][CH:14]=2)[C:9]2[C:4]1=[CH:5][CH:6]=[CH:7][CH:8]=2.O=O.S(=O)(O)[O-].[Na+].[CH3:26]O>O>[CH3:26][O:17][C:16]([C:3]1([OH:2])[C:15]2[C:10](=[N:11][CH:12]=[CH:13][CH:14]=2)[C:9]2[C:4]1=[CH:5][CH:6]=[CH:7][CH:8]=2)=[O:18]Participants
Procedure
To a stirred solution of sodium (1.1 eq, 60.1 mmol. 1.38 g) in 150 mL dry methanol was added a solution of 5-hydroxy-5H-indeno[1,2-b]pyridine-5-carboxylic acid methol ester (22) (12.3 g, 54.6 mmol) in 50 mL dry methanol. The solution was cooled in ice and, after 15 min., a flow of dry oxygen was begun and continued for 1 h. Then the reaction mixture was poured into a solution of 12 g sodium bisulfite in 200 mL water. After 30 min. the mixture was evaporated to dryness. The resulting solid was triturated with 2×100 mL acetone and filtered. The remaining inorganic salts were removed by filtration. The filtrate was evaporated to yield 24.2 g wet pink solid of (23). Drying in vacuo over phosphorus pentaoxide yielded 12.5 g crude (23). Recrystallization from ethyl acetate yielded two crops 8.06 g (61%) and 2.54 g (19%) of (23).
Workup
- temperatureThe solution was cooled in ice and, after 15 min.
- customAfter 30 min. the mixture was evaporated to dryness
- customThe resulting solid was triturated with 2×100 mL acetone
- filtrationfiltered
- customThe remaining inorganic salts were removed by filtration
- customThe filtrate was evaporated
Sources & evidence
- ORD record
- ord-5eade6dd91c14740bc75c7c56be0e798
- Source dataset
- uspto-grants-1991_12
- Patent number
- US05070100
Reaction notes
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