Dimethylformamide → 1h-Pyrazolo[4,3-b]pyridine-5,6-dicarboxylic acid,1-methyl-,5,6-dimethyl ester

HRID 742202

Reaktionsgleichung

CN(C)[CH:3]=[O:4].P(Cl)(Cl)(Cl)=[O:7].[CH3:11][N:12]1[CH:16]=[C:15]([NH:17][C:18]([CH2:28]C)=[C:19]([C:24](OC)=O)[C:20]([O:22][CH3:23])=[O:21])[CH:14]=[N:13]1.C[N+](C)=CCl.[Cl-]>ClC(Cl)C>[CH3:11][N:12]1[C:16]2[C:15](=[N:17][C:18]([C:28]([O:4][CH3:3])=[O:7])=[C:19]([C:20]([O:22][CH3:23])=[O:21])[CH:24]=2)[CH:14]=[N:13]1

Komponenten

Reaktionsbedingungen

Temperatur: -5 °C

Versuchsvorschrift

Dimethylformamide (7.4 mL, 0.096 mol) is dissolved in 125 mL dichloroethane and the mixture cooled -5° C. in an acetone/ice bath. Phosphorous oxychloride (8.9 mL, 0.095 mol) is added in one portion and the clear colorless solution is allowed to warm slowly to room temperature, gradually turning yellow. The unpurified dimethyl [(1-methylpyrazol-4-yl)amino]butenedicarboxylate is dissolved in 75 mL of dichloroethane and added chilled Viismeier reagent dropwise keeping the reaction temperature below 5° C. The mixture is allowed to warm slowly to room temperature over four hours, and then is heated to reflux for one hour. The mixture is concentrated to a solid which is chromatographed using 3:1 hexanes/ethyl acetate. The fractions containing the desired product are combined and concentrated to give the product as a white solid (16.93 g, 71.4%), melting point 148°-149° C.

Aufarbeitung

temperatureto warm slowly to room temperature
additionadded
customthe reaction temperature below 5° C
temperatureto warm slowly to room temperature over four hours
temperatureis heated
temperatureto reflux for one hour
concentrationThe mixture is concentrated to a solid which
customis chromatographed
additionThe fractions containing the desired product
concentrationconcentrated

Quellen und Nachweise

ORD-Eintrag: ord-7fb4ec3bf28d42da8b09b590b2f200d7
Quelldatensatz: uspto-grants-1996_09
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US05554579

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