Lithium Hydroxide → 8-((2,6-Difluorobenzyl)oxy)-2-methylimidazo[1,2-a]pyridine-3-carboxylic acid
Reaction equation
[F:1][C:2]1[CH:24]=[CH:23][CH:22]=[C:21]([F:25])[C:3]=1[CH2:4][O:5][C:6]1[C:7]2[N:8]([C:12]([C:16]([O:18]CC)=[O:17])=[C:13]([CH3:15])[N:14]=2)[CH:9]=[CH:10][CH:11]=1.[OH-].[Li+]>C1COCC1.CO>[F:1][C:2]1[CH:24]=[CH:23][CH:22]=[C:21]([F:25])[C:3]=1[CH2:4][O:5][C:6]1[C:7]2[N:8]([C:12]([C:16]([OH:18])=[O:17])=[C:13]([CH3:15])[N:14]=2)[CH:9]=[CH:10][CH:11]=1Participants
4
Procedure
107 g of ethyl 8-[(2,6-difluorobenzyl)oxy]-2-methylimidazo[1,2-a]pyridine-3-carboxylate (Example 5A; 300 mmol, 1 equivalent) were dissolved in 2.8 l of THF/methanol (1:1), 1.5 l of 1 N aqueous lithium hydroxide solution (1.5 mol, 5 equivalents) were added and the mixture was stirred at RT for 16 h. The organic solvents were removed under reduced pressure and the resulting aqueous solution was adjusted in an ice bath to pH 3-4 using 1 N aqueous hydrochloric acid. The resulting solid was filtered off, washed with water and isopropanol and dried under reduced pressure. This gave 92 g (95% of theory) of the title compound.
Workup
- customThe organic solvents were removed under reduced pressure
- customthe resulting aqueous solution was adjusted in an ice bath to pH 3-4
- filtrationThe resulting solid was filtered off
- washwashed with water and isopropanol
- customdried under reduced pressure
Sources & evidence
- ORD record
- ord-52fbca1205e04e4e8d59ceb3fa5f7109
- Source dataset
- uspto-grants-2015_02
- Patent number
- US08946215B2
Reaction notes
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