93% |
With dichloro(1,1'-bis(diphenylphosphanyl)ferrocene)palladium(II)*CH2Cl2; potassium acetate; In 1,4-dioxane; at 110℃;Schlenk technique; Inert atmosphere; |
General procedure: An oven dried resealable Schlenk tube was charged with 5-bromo-2-chloro-1H-pyrrolo[2,3-b]pyridine (Preparation 1c, 0.5 g, 2.07 mmol), (6-methoxy-4-methylpyridin-3-yl)boronic acid (Preparation 2, 0.35 g, 2.08 mmol), cesium carbonate (2.027 g, 6.22 mmol), 5.5 ml dioxane and 5.5 ml water. The Schlenk tube was subjected to three cycles of evacuation-backfilling with argon, and 1,1'-bis(diphenylphosphino)ferrocene-palladium(II) dichloride dichloromethane complex (0.085 g, 0.10 mmol) was added. After three further cycles of evacuation-backfilling with argon, the Schlenk tube was capped and placed in an oil bath at 100 C. After 6h, the mixture was cooled and the solvent was removed in vacuo. Water was added and product was extracted with dichloromethane and organic layer was dried (Na2SO4). The residue was purified by flash chromatography (10%, dichloromethane-methanol) to give the title compound (0.353 g, 62% yield) as a solid. <strong>[1010422-51-1]5-bromo-4-methyl-2-(trifluoromethyl)pyridine</strong> (Preparation 63a, 0.27mg, 1.13 mmol) was treated with 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) (0.57 mg, 2.27 mmol),1,1' bis(diphenylphosphino)ferrocene]dichloropalladium(II) complex with dichloromethane (56 mg, 0.07 mmol), potassium acetate (0.33 mg, 3.4 mmol) and dioxane (3 mL) as a solvent. The reaction was heated at 110C overnight according to the method described in Preparation 3a under standard conditions. The crude was purified by flash chromatography (10%, dichloromethane-methanol) to give the title compound (0.325 g, 93% yield) as a brown solid. LRMS (m/z): 288 (M+1)+ |
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With (1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride; potassium acetate; In 1,4-dioxane; at 90℃;Inert atmosphere; |
A mixture of <strong>[1010422-51-1]5-bromo-4-methyl-2-(trifluoromethyl)pyridine</strong> (150 mg, 625 mumol), bis(pinacolato)diboron (189 mg, 729 mumol), Pd(dppf)Cl2 (89 mg, 106 mumol) and potassium acetate (120 mg, 1.25 mmol) in dioxane (1 mL) was stirred under N2 at 90 C. overnight. Aqueous NH4Cl was added and the mixture was extracted with CH2Cl2. The combined organic layers were dried and the volatiles were removed under reduced pressure to yield the desired compound which was used in the next step without further purification. |