反应 #88414

反应方程式

potassium carbonate

4-chloro-2,5-dimethylpyrimidine

4,4,5,5-Tetramethyl-1,3,2-dioxaborolane

methyl 4-bromo-1-methyl-1H-pyrazole-5-carboxylate

4,4,5,5-tetramethyl-1,3,2-dioxaborolane

→

title compound

收率 110.0%

methyl 4-(2,5-dimethylpyrimidin-4-yl)-1-methyl-1H-pyrazole-5-carboxylate

收率 110.0%

溶剂

1,4-dioxane

water

triethylamine

1,4-dioxane

反应条件

后处理

1. 1
   workup.STIRRINGthe obtained mixture was then stirred for 30 minutes at the same temperature
2. 2
   workup.STIRRINGthe obtained mixture was then stirred at the same temperature
3. 3
   其他as described above for 1 hour
4. 4
   萃取the mixed solution was extracted with ethyl acetate
5. 5
   干燥was then dried over anhydrous sodium sulfate
6. 6
   workup.DISTILLATIONThe solvent was distilled away under reduced pressure
7. 7
   其他the obtained residue was purified by silica gel column chromatography (silica gel:eluent; heptane:ethyl acetate=3:1-1:1-0:1)

实验过程

4,4,5,5-Tetramethyl-1,3,2-dioxaborolane (1.5 ml) was added to a 1,4-dioxane (19 ml) solution of methyl 4-bromo-1-methyl-1H-pyrazole-5-carboxylate (1.9 g), 2-dicyclohexylphosphino-2′,6′-dimethoxy-1,1′-biphenyl (0.15 g), Tris(dibenzylideneacetone)dipalladium(0) (0.16 g), and triethylamine (3.7 ml). The obtained mixture was stirred in a nitrogen atmosphere at 100° C. for 30 minutes. Thereafter, 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (1.5 ml) was added to the reaction solution, and the obtained mixture was then stirred for 30 minutes at the same temperature as described above. Thereafter, an aqueous solution (3.9 ml) of potassium carbonate (3.6 g) and a 1,4-dioxane (4 ml) solution of 4-chloro-2,5-dimethylpyrimidine (1.0 g) were successively added to the reaction solution, and the obtained mixture was then stirred at the same temperature as described above for 1 hour. Thereafter, water was added to the reaction solution, and the mixed solution was extracted with ethyl acetate and was then dried over anhydrous sodium sulfate. The solvent was distilled away under reduced pressure, and the obtained residue was purified by silica gel column chromatography (silica gel:eluent; heptane:ethyl acetate=3:1-1:1-0:1), so as to obtain the title compound (1.9 g) in the form of an orange liquid.

来源