Methanol → 3,5-dimethyl-1H-pyrrole-2-carboxylic acid
Reaction equation
[CH3:1][C:2]1[CH:6]=[C:5]([CH3:7])[NH:4][C:3]=1[C:8]([O:10]CC)=[O:9].CO.[OH-].[Na+]>C1COCC1>[CH3:1][C:2]1[CH:6]=[C:5]([CH3:7])[NH:4][C:3]=1[C:8]([OH:10])=[O:9]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 75 °C
Procedure
To a solution of ethyl 3,5-dimethyl-2-pyrrolecarboxylate (Aldrich) (504 mg, 3 mmol) in THF/H20/MeOH (5:1:1, 30 ml) was added NaOH (480 mg, 12 mmol) in H20 (12 ml). The mixture was stirred at 75° C. overnight. The homogeneous mixture was washed with ether. To the aqueous layer was added a saturated aqueous KHSO4 solution until the pH was about 3. The solution was then extracted with dichloromethane. The extracts were dried over MgSO4 and evaporated. The residue was purified on silica (ethylacetate/methanol 90/10) to give the title compound (375 mg, 90%).
Workup
- washThe homogeneous mixture was washed with ether
- additionTo the aqueous layer was added a saturated aqueous KHSO4 solution until the pH was about 3
- extractionThe solution was then extracted with dichloromethane
- dry with materialThe extracts were dried over MgSO4
- customevaporated
- customThe residue was purified on silica (ethylacetate/methanol 90/10)
Sources & evidence
- ORD record
- ord-a3aa22aeeb774989b276a5159dad48b7
- Source dataset
- uspto-grants-2005_06
- Patent number
- US06911458B2
Reaction notes
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