反応 #41161

反応方程式

(Tetrahydro-pyran-4-yl)-hydrazine hydrochloride

ethyl (ethoxymethylene)-cyanoacetate

sodium acetate

→

5-amino-1-(tetrahydro-pyran-4-yl)-1H-pyrazole-4-carboxylic acid ethyl ester

収率 92.3%

溶媒

ethanol

反応条件

後処理

1. 1
   温度After cooling to room temperature
2. 2
   濃縮the reaction was concentrated
3. 3
   その他the residue was partitioned between methylene chloride and water
4. 4
   その他The organic phase was separated
5. 5
   洗浄washed with water
6. 6
   抽出Each aqueous phase was back extracted with methylene chloride
7. 7
   乾燥dried over sodium sulfate
8. 8
   濃縮concentrated in vacuo
9. 9
   その他The crude material was purified by flash chromatography
10. 10
    洗浄eluting with 60-100% ethyl acetate/hexanes

実験手順

(Tetrahydro-pyran-4-yl)-hydrazine hydrochloride (1.975 g, 12.94 mmol), ethyl (ethoxymethylene)-cyanoacetate (1.958 g, 11.57 mmol) and sodium acetate (1.370 g; 16.70 mmol) were combined in ethanol (16 mL). The mixture was heated at 80-85° C. for 17 hours. After cooling to room temperature, the reaction was concentrated and the residue was partitioned between methylene chloride and water. The organic phase was separated and washed with water and then brine. Each aqueous phase was back extracted with methylene chloride. The two organic phases were combined, dried over sodium sulfate and concentrated in vacuo. The crude material was purified by flash chromatography eluting with 60-100% ethyl acetate/hexanes to give 5-amino-1-(tetrahydro-pyran-4-yl)-1H-pyrazole-4-carboxylic acid ethyl ester (2.554 g, 92%).

出典