Hydrochloric Acid → Ethyl 3-hydroxy-1-isopropylpyrazole-4-carboxylate

HRID 2102257Notes

Reaction equation

C[O-].[Na+].CCO[CH:7]=[C:8]([C:14]([O:16]CC)=O)[C:9]([O:11][CH2:12][CH3:13])=[O:10].[CH:19]([NH:22][NH2:23])([CH3:21])[CH3:20].Cl>C(O)C.[Cl-].[Na+].O>[OH:16][C:14]1[C:8]([C:9]([O:11][CH2:12][CH3:13])=[O:10])=[CH:7][N:22]([CH:19]([CH3:21])[CH3:20])[N:23]=1

Participants

Conditions

Temperature: 80 °C

Procedure

To a solution of sodium methoxide (23 g) in ethanol (150 mL) were added diethyl ethoxymethylene malonate (32.7 g) and isopropyl hydrazine (11.2 g) at room temperature. The mixture was stirred at 80° C. for 4 hours and stirred at 100° C. for another 2 hours. The reaction mixture was poured into 2 mol/L hydrochloric acid (300 mL). After the mixture was diluted with brine, the mixture was extracted with ethyl acetate. The organic layer was washed with brine and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure and the obtained residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane=1/5) to give 10.5 g of the title compound.

Workup

stirringstirred at 100° C. for another 2 hours
extractionthe mixture was extracted with ethyl acetate
washThe organic layer was washed with brine
dry with materialdried over anhydrous magnesium sulfate
customThe solvent was removed under reduced pressure
customthe obtained residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane=1/5)

Sources & evidence

ORD record: ord-7970bb2cc9344010b16fadce33b0932b
Source dataset: uspto-grants-2009_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07576064B2

Reaction notes

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