반응 #155929

반응 방정식

Na2CO3

6-bromoindazole

4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester

K2CO3

→

4-(1H-indazol-6-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester

용매

1,4-dioxane

반응 조건

후처리

1. 1
   온도cooled to room temperature
2. 2
   추출The resulting mixture was extracted with EtOAc (3×)
3. 3
   세척The combined extracts were washed with brine
4. 4
   건조dried over Na2SO4
5. 5
   여과The resulting mixture was filtered
6. 6
   농축concentrated under reduced pressure
7. 7
   기타the residue purified by flash chromatography on silica-gel (gradient eluent heptane to 60% EtOAc in heptane)

실험 절차

To a mixture of 6-bromoindazole (2.0 g, 10.2 mmol), 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (3.5 g, 11.2 mmol) and Pd(PPh3)4 (1.2 g, 1.0 mmol) under N2 were added 1,4-dioxane (80 mL), followed by addition of K2CO3 (2 M in H2O, 20 mL, 40 mmol). The resulting mixture was heated at 110° C. for 16 h, then cooled to room temperature. The resulting mixture was then treated with saturated Na2CO3 aqueous solution. The resulting mixture was extracted with EtOAc (3×). The combined extracts were washed with brine and then dried over Na2SO4. The resulting mixture was filtered, concentrated under reduced pressure, and the residue purified by flash chromatography on silica-gel (gradient eluent heptane to 60% EtOAc in heptane) to yield 4-(1H-indazol-6-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester as brownish foam solid.

출처