Potassium Carbonate → 6-Chloro-5-(4-cyclohexylphenyl)-1H-indazole-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 5,5,5′,5′-tetramethyl-2,2′-bi-1,3,2-dioxaborinane (75.0 mg, 0.22 mmol), oven dried potassium acetate (94.1 mg, 0.95 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (19.0 mg, 0.023 mmol), and 1-bromo-4-cyclohexylbenzene (49.5 mg, 0.21 mmol) in 1,4-dioxane (2 mL) was degassed with N2 for 10 minutes, and subjected to microwave irradiation at 115° C. for one hour. The black reaction mixture was cooled, filtered through cotton, and concentrated in vacuo to give a dark solid. To the dark solid was added 5-bromo-6-chloro-1H-indazole-3-carboxylic acid (55.6 mg, 0.20 mmol), 2 N aqueous potassium carbonate solution (0.40 mL, 0.81 mmol) and [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichloromethane adduct (16.3 mg, 0.020 mmol). The reaction mixture was diluted with degassed toluene (1 mL) and EtOH (1 mL), and heated at 110° C. for 18 hours in a sealed reaction vessel. The cooled reaction mixture was concentrated in vacuo and partitioned between 2 N citric acid (15 mL) and EtOAc (15 mL). The layers were separated, and the aqueous phase was extracted with EtOAc (15 mL). The combined organic layers were dried over Na2SO4 and concentrated in vacuo to give a dark oil, which was purified by reverse phase HPLC (Column: Waters XBridge C18 19×100 mm, 5 μm; Mobile phase A: 0.03% NH4OH in water (v/v); Mobile phase B: 0.03% NH4OH in MeCN (v/v); 80.0% H2O/20.0% MeCN linear to 40% H2O/60% MeCN in 8.5 min, 40% H2O/60% MeCN linear to 0% H2O/100% MeCN in 0.5 min, HOLD at 0% H2O/100% MeCN to 10.0 min. Flow: 25 mL/min) to give the title compound (6.2 mg, 9% yield). MS (ES+) 355.1 (M+H)+. Retention time=3.65 minutes (Column: Waters Atlantis dC18 4.6×50 mm, 5 μm; Mobile phase A: 0.05% TFA in water (v/v); Mobile phase B: 0.05% TFA in MeCN (v/v); Gradient: 95:5 A:B linear to 5:95 A:B in 4.0 min, hold at 5:95 A:B to 5.0 min. Flow: 2 mL/min).

Provenance & Evidence