Sodium Hydroxide → 5-tert-butyl-4-methoxy-2-methyl-2H-pyrazole-3-carboxylic acid
Reaktionsgleichung
C([O:3][C:4]([C:6]1[N:7]([CH3:17])[N:8]=[C:9]([C:13]([CH3:16])([CH3:15])[CH3:14])[C:10]=1[O:11][CH3:12])=[O:5])C.[OH-].[Na+]>CO>[C:13]([C:9]1[C:10]([O:11][CH3:12])=[C:6]([C:4]([OH:5])=[O:3])[N:7]([CH3:17])[N:8]=1)([CH3:16])([CH3:14])[CH3:15]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
5-tert-Butyl-4-methoxy-2-methyl-2H-pyrazole-3-carboxylic acid ethyl ester (52.8 mg, 0.220 mmol, prepared as described in the previous step) was dissolved in MeOH (1 mL) then 2 M NaOH (143 μL, 0.286 mmol) was added. The resulting mixture was stirred at room temperature for 18 h and the solvent was removed under reduced pressure. The residue was dissolved in H2O (10 mL) and acidified to pH˜2 using 3 M HCl. The aqueous layer was extracted with EtOAc (3×5 mL) and the combined organic extracts were dried over MgSO4 and filtered. The solvent was removed under reduced pressure to yield 5-tert-butyl-4-methoxy-2-methyl-2H-pyrazole-3-carboxylic acid. 1H-NMR (400 MHz, CDCl3) δ: 11.65 (br. s., 1H), 4.08 (s, 3H), 3.89 (s, 3H), 1.37 (s, 9H).