Hydrochloric Acid → 4,5-Diethyl 1-methyl-1H-pyrazole-4,5-dicarboxylate

HRID 2382723

Reaktionsgleichung

Reaktionsgleichung von HRID 2382723
[CH3:1][NH:2]N.Cl.[CH2:5]([O:7][C:8](=[O:21])[C:9](=[CH:17][N:18](C)C)[C:10](=O)[C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH3:6]>C(O)C>[CH2:14]([O:13][C:11]([C:10]1[N:2]([CH3:1])[N:18]=[CH:17][C:9]=1[C:8]([O:7][CH2:5][CH3:6])=[O:21])=[O:12])[CH3:15]

Komponenten

5

Reaktionsbedingungen

Temperatur
60 °C

Versuchsvorschrift

Under an atmosphere of argon, methylhydrazine (1.15 g, 25 mmol) and HCl (36.5% in water, 2.5 ml) were added to a solution of 2-dimethylaminomethylene-3-oxo-succinic acid diethyl ester (6.07 g, 25 mmol, obtained by the method of Hanzlowsky et al., J. Heterocyclic Chem. 2003, 40(3), 487-498) in ethanol (200 ml). The mixture was heated to 60° C. until HPLC analysis indicated the disappearance of the starting material (2 h). The solvent was evaporated, and the residue was taken up in dichloromethane and washed (water). The organic layer was dried (Na2SO4), the solvent was evaporated and the title compound (2.06 mg, 36%) was isolated from the mixture by column chromatography (silica gel, heptane:ethyl acetate=100:0-60:40). (The regioisomeric 1-methyl-1H-pyrazole-3,4-dicarboxylic acid diethyl ester can also be isolated, and can be distinguished from the desired product by NOE-1H-NMR.) MS (m/e)=227.2 [M+H+].

Aufarbeitung

  1. customobtained by the method of Hanzlowsky et al., J
  2. customthe disappearance of the starting material (2 h)
  3. customThe solvent was evaporated
  4. washwashed (water)
  5. dry with materialThe organic layer was dried (Na2SO4)
  6. customthe solvent was evaporated

Quellen und Nachweise

ORD-Eintrag
ord-0269e6d90c5045898f6616a901b0d342
Quelldatensatz
uspto-grants-2012_09
Patentnummer
US08263584B2

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