Sodium Hydroxide → 4-(4-Fluoro-phenyl)-5,6-dihydro-2H-pyridine-1,3-dicarboxylic acid 1-tert-butyl ester
Reaction equation
C[O:2][C:3]([C:5]1[CH2:6][N:7]([C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH2:8][CH2:9][C:10]=1[C:11]1[CH:16]=[CH:15][C:14]([F:17])=[CH:13][CH:12]=1)=[O:4].[OH-].[Na+]>O1CCOCC1>[C:21]([O:20][C:18]([N:7]1[CH2:8][CH2:9][C:10]([C:11]2[CH:12]=[CH:13][C:14]([F:17])=[CH:15][CH:16]=2)=[C:5]([C:3]([OH:4])=[O:2])[CH2:6]1)=[O:19])([CH3:24])([CH3:22])[CH3:23]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of 4-(4-fluoro-phenyl)-5,6-dihydro-2H-pyridine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl ester (6.8 g, 20 mmol), 100 ml 1,4-dioxane and 100 ml 2 M NaOH was stirred at RT for 20 h. After extraction of the reaction mixture with two portions of tert-butyl methyl ether, the combined organic layers were extracted with 1 M aqueous sodium hydroxide solution (100 ml). The combined aqueous layers were cooled to 0° C. by addition of ice (150 g) and acidified to pH 1 with ice-cold 4 M aqueous hydrochloric acid solution (70 ml). The aqueous layer was extracted with three 150 ml-portions of ethyl acetate. The combined organic layers were washed with brine (50 ml), dried over sodium sulfate and concentrated in vacuo. Crystallization of the crude acid (6.4 g) from a mixture of n-heptane and ethyl acetate (19:1, 120 ml) gave the title compound as white crystals (5.1 g, 78%).
Workup
- extractionAfter extraction of the reaction mixture with two portions of tert-butyl methyl ether
- extractionthe combined organic layers were extracted with 1 M aqueous sodium hydroxide solution (100 ml)
- temperatureThe combined aqueous layers were cooled to 0° C. by addition of ice (150 g)
- extractionThe aqueous layer was extracted with three 150 ml-portions of ethyl acetate
- washThe combined organic layers were washed with brine (50 ml)
- dry with materialdried over sodium sulfate
- concentrationconcentrated in vacuo
- customCrystallization of the crude acid (6.4 g)
- additionfrom a mixture of n-heptane and ethyl acetate (19:1, 120 ml)
Sources & evidence
- ORD record
- ord-1ffb5142c9e34b16b36ff84157028eb1
- Source dataset
- uspto-grants-2011_01
- Patent number
- US07872022B2
Reaction notes
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