Hydrochloric Acid → HCID 4542029, compound
Reaction equation
C([O:3][C:4]([C:6]1[CH:10]=[C:9]([CH:11]2[CH2:15][CH2:14][CH2:13][CH2:12]2)[NH:8][N:7]=1)=[O:5])C.[OH-].[Na+].Cl>O1CCOCC1>[CH:11]1([C:9]2[NH:8][N:7]=[C:6]([C:4]([OH:5])=[O:3])[CH:10]=2)[CH2:12][CH2:13][CH2:14][CH2:15]1Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 50 °C
Procedure
5-Cyclopentyl-1H-pyrazol-3-carboxylic acid ethyl ester (17.1 g, 82 mmol) and 1M NaOH solution (205 ml, 205 mmol) were dissolved in 1,4-dioxan (300 ml) and the reaction was heated to 50° C. under nitrogen and stirred for 3 hours. The reaction mixture was cooled, adjusted to pH 2 using concentrated hydrochloric acid and the solvent was removed under reduced pressure. The residual solid was azeotrped with toluene (2×30 ml), dissolved in ethyl acetate (500 ml) and washed with water (200 ml). The aqueous phase was removed, extracted with ethyl acetate (2×200 ml) and the combined organic extracts were dried over MgSO4. The solvent was removed under reduced pressure and the residue was azeotrped with dichloromethane (2×50 ml) to give 5-cyclopentyl-1H-pyrazol-3-carboxylic acid (13 g) as a white solid. 1H NMR (400 MHz, DMSO-D6): δ=12.75-12.88 (2H, brs), 6.43 (1H, s), 2.97-3.08 (1H, quin), 1.91-2.02 (2H, m), 1.50-1.76 (6H, 2×m) ppm. LRMS (electrospray): m/z [M−H]+ 179. Anal. Found C, 59.72; H, 6.74; N, 15.37. C9H12N2 requires C, 59.99; H, 6.71; N, 15.55%.
Workup
- temperatureThe reaction mixture was cooled
- customthe solvent was removed under reduced pressure
- dissolutiondissolved in ethyl acetate (500 ml)
- washwashed with water (200 ml)
- customThe aqueous phase was removed
- extractionextracted with ethyl acetate (2×200 ml)
- dry with materialthe combined organic extracts were dried over MgSO4
- customThe solvent was removed under reduced pressure
Sources & evidence
- ORD record
- ord-e1df2d1ba4f94cc89c62d99db06edb65
- Source dataset
- uspto-grants-2005_11
- Patent number
- US06967204B2
Reaction notes
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