2-Propenoic acid, 2-cyano-3-ethoxy-, ethyl ester → ethyl 5-amino-1-cyclopentyl-1H-pyrazole-4-carboxylate

HRID 12886

Reaktionsgleichung

Reaktionsgleichung von HRID 12886
Cl.[CH:2]1([NH:7][NH2:8])[CH2:6][CH2:5][CH2:4][CH2:3]1.C(O[CH:12]=[C:13]([C:19]#[N:20])[C:14]([O:16][CH2:17][CH3:18])=[O:15])C.C([O-])(=O)C.[Na+]>C(O)C>[CH2:17]([O:16][C:14]([C:13]1[CH:12]=[N:8][N:7]([CH:2]2[CH2:6][CH2:5][CH2:4][CH2:3]2)[C:19]=1[NH2:20])=[O:15])[CH3:18]

Komponenten

5

Reaktionsbedingungen

Temperatur
70 °C

Versuchsvorschrift

Cyclopentyl-hydrazine hydrochloride (1.000 g; 7.32 mmol), ethyl (ethoxymethylene)-cyanoacetate (1.026 g, 6.61 mmol) and anhydrous sodium acetate (0.644 g, 7.85 mmol) were combined in ethanol (10 mL) and heated at 70° C. for 20 hours. After cooling to room temperature, ethanol was removed in vacuo and the residue was partitioned between methylene chloride and water. The organic phase was washed sequentially with water and brine. Each aqueous phase was back extracted with a single portion of methylene chloride. The two organic phases were combined, dried over sodium sulfate and concentrated. Purification by flash chromatography, eluting with 10-40% EtOAc/hexanes yielded 5-amino-1-cyclopentyl-1H-pyrazole-4-carboxylic acid ethyl ester (1.170 g, 73%). Mass spectrum: m/z: 224.1 (M+H).

Aufarbeitung

  1. temperatureAfter cooling to room temperature
  2. customethanol was removed in vacuo
  3. customthe residue was partitioned between methylene chloride and water
  4. washThe organic phase was washed sequentially with water and brine
  5. extractionEach aqueous phase was back extracted with a single portion of methylene chloride
  6. dry with materialdried over sodium sulfate
  7. concentrationconcentrated
  8. customPurification by flash chromatography
  9. washeluting with 10-40% EtOAc/hexanes

Quellen und Nachweise

ORD-Eintrag
ord-660058880d6144ccbdfae5625f97875b
Quelldatensatz
uspto-grants-2010_06
Patentnummer
US07728029B2

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