Water → HCID 19890291, compound

To a 15 ml solution of ethyl 4-benzyloxy-1,3-dimethylpyrazol-5-carboxylate (2.5 g, 9.1 mmol) in anhydrous tetrahydrofuran (hereinafter, referred to as THF) was added lithium aluminium hydride (0.2 g, 5.3 mmol) under ice-cooling. After stirring at room temperature for one hour, the reaction mixture was poured into water. The mixture was extracted with ethyl acetate, and the extract was successively washed with water and saturated brine, dried over anhydrous sodium sulfate and concentrated in vacuo. To the residue (2 g) was added toluene (5 ml) and thionyl chloride (2 g) and the resulting mixture was heated under reflux for one hour. After low boiling substances were evaporated, the residue was combined with ethyl acetate. The mixture was successively washed with, water, aqueous sodium bicarbonate, water, and saturated brine, dried over anhydrous sodium sulfate and concentrated in vacuo. To a 5 ml solution of the residue in dimethyl sulfoxide (hereinafter, referred to as DMSO) was added sodium cyanide (0.43 g, 8.8 mmol) and the mixture was stirred at room temperature and left to stand overnight. The reaction mixture was poured into water. The mixture was extracted with ethyl acetate, and the extract was successively washed with water, and saturated brine, dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was chromatographed over silica gel (eluent; ethyl acetate/n-hexane=1:2) to obtain (4-benzyloxy-1,3-dimethylpyrazol-5-yl)acetonitrile (1.6 g, 6.6 mmol, 73%).

1. temperaturecooling
2. extractionThe mixture was extracted with ethyl acetate
3. washthe extract was successively washed with water and saturated brine
4. dry with materialdried over anhydrous sodium sulfate
5. concentrationconcentrated in vacuo
6. additionTo the residue (2 g) was added toluene (5 ml) and thionyl chloride (2 g)
7. temperaturethe resulting mixture was heated
8. temperatureunder reflux for one hour
9. customAfter low boiling substances were evaporated
10. washThe mixture was successively washed with, water, aqueous sodium bicarbonate, water, and saturated brine
11. dry with materialdried over anhydrous sodium sulfate
12. concentrationconcentrated in vacuo
13. stirringthe mixture was stirred at room temperature
14. waitleft
15. waitto stand overnight
16. extractionThe mixture was extracted with ethyl acetate
17. washthe extract was successively washed with water, and saturated brine
18. dry with materialdried over anhydrous sodium sulfate
19. concentrationconcentrated in vacuo
20. customThe residue was chromatographed over silica gel (eluent; ethyl acetate/n-hexane=1:2)

ORD record

ord-ecd56a82e8ae4d1884b31b3f817c8461

Source dataset

uspto-grants-1992_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05128481