反応 #575984

反応方程式

methylamine

ethyl 1-(2-chloro-5-hydroxycarbonylphenyl)-5-cyclopropyl-1H-pyrazole-4-carboxylate

→

title compound

収率 77.1%

Ethyl 1-(2-chloro-5-methylaminocarbonylphenyl)-5-cyclopropyl-1H-pyrazole-4-carboxylate

収率 77.1%

溶媒

CH2Cl2

thionyl chloride

反応条件

後処理

1. 1
   温度at reflux for 2 h under a nitrogen atmosphere
2. 2
   濃縮The resulting solution was concentrated in vacuo
3. 3
   その他partitioned between ethyl acetate and HCl (1 M aq)
4. 4
   洗浄The organic layer was washed with brine, NaHCO3 (sat aq sol), and brine
5. 5
   乾燥dried over MgSO4
6. 6
   ろ過filtered
7. 7
   濃縮concentrated in vacuo
8. 8
   その他The residue was purified by flash 40M™ chromatography (75:25 ethyl acetate/hexanes)

実験手順

A solution of ethyl 1-(2-chloro-5-hydroxycarbonylphenyl)-5-cyclopropyl-1H-pyrazole-4-carboxylate (1.32 g, 3.73 mmol) in thionyl chloride (7.5 mL) was heated at reflux for 2 h under a nitrogen atmosphere. The resulting solution was concentrated in vacuo. A solution of the residue in anhydrous CH2Cl2 (10 mL) under a nitrogen atmosphere was treated with methylamine (2 M solution in THF, 9.33 mL, 18.7 mmol) followed by a catalytic amount of 4-dimethylaminopyridine. The resulting mixture was stirred for 6 h and partitioned between ethyl acetate and HCl (1 M aq). The organic layer was washed with brine, NaHCO3 (sat aq sol), and brine, dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by flash 40M™ chromatography (75:25 ethyl acetate/hexanes) to afford 1.00 g (77% yield) of the title compound.

出典