Hydrochloric Acid → 6-Chloro-5-(4-(2-hydroxyethoxy)phenyl)-1H-indazole-3-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A suspension of 2-(4-bromophenoxy)ethanol (100 mg, 0.46 mmol), 5,5,5′,5′-tetramethyl-2,2′-bi-1,3,2-dioxaborinane (173 mg, 0.50 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (38.0 mg, 0.025 mmol) and potassium acetate (135 mg, 1.38 mmol) in 1,4-dioxane (1 mL) was sealed in a pressure tube and heated to 130° C. for 1 hour. To the mixture was added 5-bromo-6-chloro-1H-indazole-3-carboxylic acid (100 mg, 0.36 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (14.7 mg, 0.018 mmol), 2 N aqueous potassium carbonate solution (0.5 mL, 1.0 mmol) and EtOH (2 mL). The mixture was sealed and heated to 130° C. for 1 hour. Water (3 mL) was added to the reaction mixture, followed by 1 N HCl solution to adjust the pH to 2. The layers were separated and the aqueous layer was extracted with EtOAc (3×5 mL). The combined organic layers were dried over Na2SO4 and concentrated in vacuo. The crude material was purified by reverse phase HPLC (Column: Waters Sunfire C18 19×100 mm, 5 μm; Mobile phase A: 0.05% Formic acid in water (v/v); Mobile phase B: 0.05% Formic acid in MeCN (v/v); HOLD at 75.0% H2O/25.0% MeCN for 1.0 min. 75.0% H2O/25.0% MeCN linear to 45.0% H2O/55.0% MeCN in 6.75 min, linear to 0% H2O/100% MeCN to 7.0 min. HOLD at 0% H2O/100% MeCN from 7.0 to 8.0 min. Flow: 30 ml/min) to afford the title compound (23.1 mg, 15% yield). MS (ES+) 333.0 (M+H)+. Retention time=2.19 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