反应详情

温度

100 °C

A solution containing 2.75 g of (4-methoxybenzyl)hydrazine dihydrochloride in 50 ml of toluene was treated with 1.7 ml of triethylamine at rt and then stirred for 5 min. The mixture was then treated with 1.32 ml of methyl acetoacetate and heated at 100° C. for 15 min. The solvent was evaporated under reduced pressure and then the residue partitioned between dichloromethane/10% citric acid and extracted three times. Combined extracts were washed with brine, then dried over anhydrous magnesium sulphate, filtered and evaporated to give a yellow solid. The solid was purified by flash chromatography on silica gel using methanol/dichloromethane (1:49) for the elution to give 2.3 g of 2-(4-methoxybenzyl)-5-methyl-2H-pyrazol-3-ol as a white solid. Mass spectrum (ES) m/z 219 [M+H]+.

1. customThe solvent was evaporated under reduced pressure
2. customthe residue partitioned between dichloromethane/10% citric acid
3. extractionextracted three times
4. washCombined extracts were washed with brine
5. dry with materialdried over anhydrous magnesium sulphate
6. filtrationfiltered
7. customevaporated
8. customto give a yellow solid
9. customThe solid was purified by flash chromatography on silica gel
10. washfor the elution