반응 #41161

반응 방정식

(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

수율 92.3%

용매

ethanol

반응 조건

후처리

1. 1
   온도After cooling to room temperature
2. 2
   농축the reaction was concentrated
3. 3
   기타the residue was partitioned between methylene chloride and water
4. 4
   기타The organic phase was separated
5. 5
   세척washed with water
6. 6
   추출Each aqueous phase was back extracted with methylene chloride
7. 7
   건조dried over sodium sulfate
8. 8
   농축concentrated in vacuo
9. 9
   기타The crude material was purified by flash chromatography
10. 10
    세척eluting with 60-100% ethyl acetate/hexanes

실험 절차

(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%).

출처