反应详情

A mixture of 17 parts of (4-methoxyphenyl)hydrazine hydrochloride, 14 parts of 4,4-dimethoxy-2-butanone, 14 parts of potassium carbonate and 240 parts of ethanol is stirred and refluxed for 2 hours. The reaction mixture is evaporated and the residue is stirred and refluxed for 1 hour with 200 parts of a hydrochloric acid solution 10%. The solvent is evaporated and the residue is neutralized with ammonium hydroxide. The product is extracted three times with 2,2'-oxybispropane. The combined extracts are washed with water, dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using trichlormethane as eluent. The pure fractions are collected and the eluent is evaporated. The residue is crystallized from hexane. The product is filtered off and dried, yielding 2.4 parts of 1-(4-methoxyphenyl)-3-methyl-1H-pyrazole.

1. temperaturerefluxed for 2 hours
2. customThe reaction mixture is evaporated
3. stirringthe residue is stirred
4. temperaturerefluxed for 1 hour with 200 parts of a hydrochloric acid solution 10%
5. customThe solvent is evaporated
6. extractionThe product is extracted three times with 2,2'-oxybispropane
7. washThe combined extracts are washed with water
8. customdried
9. filtrationfiltered
10. customevaporated
11. customThe residue is purified by column-chromatography over silica gel
12. customThe pure fractions are collected
13. customthe eluent is evaporated
14. customThe residue is crystallized from hexane
15. filtrationThe product is filtered off
16. customdried