Реакция #41156

Уравнение реакции

Cyclohexylhydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

5-amino-1-cyclohexyl-1H-pyrazole-4-carboxylic acid ethyl ester

Выход 92.9%

Растворители

ethanol

Условия реакции

Обработка

1. 1
   Температураthen cooled to room temperature
2. 2
   Концентрированиеconcentrated
3. 3
   ДругоеThe residue was partitioned between methylene chloride and water
4. 4
   ЭкстракцияThe separated aqueous phase was extracted with a second portion of methylene chloride
5. 5
   ПромывкаThe organic phases were successively washed with water and brine
6. 6
   Сушкаdried over sodium sulfate
7. 7
   Концентрированиеconcentrated in vacuo
8. 8
   ДругоеThe residue was purified by flash chromatography
9. 9
   Промывкаeluting with a gradient of 25-70% ethyl acetate/hexanes

Методика

Cyclohexylhydrazine hydrochloride (3.057 g, 20.29 mmol, CAS #24214-73-1, purchased from Aldrich) was combined with ethyl (ethoxymethylene)-cyanoacetate (3.390 g, 20.04 mmol) and anhydrous sodium acetate (2.080 g, 25.36 mmol) in 30 mL ethanol. The mixture was heated at 70° C. for 16 hours then cooled to room temperature and concentrated. The residue was partitioned between methylene chloride and water. The separated aqueous phase was extracted with a second portion of methylene chloride. The organic phases were successively washed with water and brine and then combined, dried over sodium sulfate and concentrated in vacuo. The residue was purified by flash chromatography eluting with a gradient of 25-70% ethyl acetate/hexanes to give 5-amino-1-cyclohexyl-1H-pyrazole-4-carboxylic acid ethyl ester (4.42 g, 92%). Mass spectrum: m/z: 238.1 (M+H).

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