Hydrochloric Acid → 2-(5-chloro-4-hydroxy-6-oxo-6H-pyridazin-1-yl)-3-cyclopentyl-propionic acid
Reaction equation
C[O:2][C:3](=[O:20])[CH:4]([N:11]1[C:16](=[O:17])[C:15]([Cl:18])=[C:14](Cl)[CH:13]=[N:12]1)[CH2:5][CH:6]1[CH2:10][CH2:9][CH2:8][CH2:7]1.[OH-:21].[Na+].Cl>C(OCC)(=O)C>[Cl:18][C:15]1[C:16](=[O:17])[N:11]([CH:4]([CH2:5][CH:6]2[CH2:10][CH2:9][CH2:8][CH2:7]2)[C:3]([OH:2])=[O:20])[N:12]=[CH:13][C:14]=1[OH:21]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of 3-cyclopentyl-2-(4,5-dichloro-6-oxo-6H-pyridazin-1-yl)-propionic acid methyl ester (Intermediate 79 step 1, 18.0 g, 56.4 mmol) in a 4N aqueous sodium hydroxide solution (140 mL) was stirred at 60° C. overnight. The reaction solution was acidified with a 6N aqueous hydrochloric acid solution to pH=2˜3. Ethyl acetate was added to the solution and was stirred for 10 min. The aqueous phase was extracted with ethyl acetate, the combined organics were washed with a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. The residue was washed with diethyl ether (50 mL) to afford 2-(5-chloro-4-hydroxy-6-oxo-6H-pyridazin-1-yl)-3-cyclopentyl-propionic acid as a white solid (14.5 g, 90%).
Workup
- extractionThe aqueous phase was extracted with ethyl acetate
- washthe combined organics were washed with a saturated aqueous sodium chloride solution
- dry with materialdried over anhydrous sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
- washThe residue was washed with diethyl ether (50 mL)
Sources & evidence
- ORD record
- ord-4f3fc909d9d04299b3f5a60e6cc33cc7
- Source dataset
- uspto-grants-2012_09
- Patent number
- US08258134B2
Reaction notes
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