反应详情

温度

110 °C

A solution containing 1.0 g of 2-(4-methoxybenzyl)-5-methyl-2H-pyrazol-3-ol in 30 ml of dioxan was treated with 679 mg of calcium hydroxide and 800 μl of benzoyl chloride, then heated at 110° C. for 2 h. To the mixture was added 20 drops of water and the mixture heated for a further 2 h. The solvent was evaporated under reduced pressure and the residue partitioned between dichloromethane/10% citric acid. The organic phase was washed with brine, then dried over anhydrous magnesium sulphate, filtered and evaporated to give yellow oil. The oil was purified twice by flash chromatography on silica gel, initially using methanol/dichloromethane (1:49) to give a red solid, then ethyl acetate/hexane (1:1 to 2:1) for the elutions to give 400 mg of [5-hydroxy-1-(4-methoxybenzyl)-3-methyl-1H-pyrazol-4-yl]-phenyl-methanone as a yellow gum. Mass spectrum (ES) m/z 323 [M+H]+.

1. temperaturethe mixture heated for a further 2 h
2. customThe solvent was evaporated under reduced pressure
3. customthe residue partitioned between dichloromethane/10% citric acid
4. washThe organic phase was washed with brine
5. dry with materialdried over anhydrous magnesium sulphate
6. filtrationfiltered
7. customevaporated
8. customto give yellow oil
9. customThe oil was purified twice by flash chromatography on silica gel, initially using methanol/dichloromethane (1:49)
10. customto give a red solid