Hydrochloric Acid → Methyl 4-benzyloxy-3-carboxy-1H-pyrazole-5-carboxylate

HRID 1453871

Reaktionsgleichung

[CH2:1]([O:8][C:9]1[C:10]([C:18]([O:20][CH3:21])=[O:19])=[N:11][NH:12][C:13]=1[C:14]([O:16]C)=[O:15])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.Cl.C(OCC)(=O)C>CN(C)N.O>[CH2:1]([O:8][C:9]1[C:13]([C:14]([OH:16])=[O:15])=[N:12][NH:11][C:10]=1[C:18]([O:20][CH3:21])=[O:19])[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Komponenten

Reaktionsbedingungen

Temperatur: 35 °C

Versuchsvorschrift

Dimethyl 4-benzyloxy-1H-pyrazole-3,5-dicarboxylate (25 g, 86 mmol) was dissolved in N,N-dimethylhydrazine (75 mL) and the stirred mixture heated to reflux under nitrogen atmosphere for 30 hours. The solvent was removed in vacuo to give a white solid. The residue was dissolved in water (200 mL), 1N HCl (75 mL), and ethyl acetate (100 mL). The mixture was stirred and warmed to 35° C. until all the solids had dissolved. The layers were then separated and the aqueous layer was extracted with more ethyl acetate (3×100 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated under reduced pressure to give the product as a white solid. 1H NMR (400 MHz, d6-DMSO) δ 13.2 (br s, 1H), 7.3-7.45 (m, 5H), 5.09 (s, 2H), 3.81 (s, 3H); ES MS (M+1)=277.

Aufarbeitung

temperaturethe stirred mixture heated
temperatureto reflux under nitrogen atmosphere for 30 hours
customThe solvent was removed in vacuo
customto give a white solid
dissolutionhad dissolved
customThe layers were then separated
extractionthe aqueous layer was extracted with more ethyl acetate (3×100 mL)
dry with materialThe combined organic extracts were dried over Na2SO4
filtrationfiltered
concentrationconcentrated under reduced pressure

Quellen und Nachweise

ORD-Eintrag: ord-f222b583c60f474eb8d4ab9a0b4ef3a0
Quelldatensatz: uspto-grants-2009_01
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US07476666B2

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