Sodium Hydroxide → 6-amino-5-ethynyl-1H-indazole-7-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 200 mg (0.93 mmol) of 6-amino-5-ethynyl-1H-indazole-7-carboxylic acid methyl ester in 4.2 mL of dioxane and 0.2 mL of methanol is added 2.3 mL (2.3 mmol) of a 1N aqueous solution of NaOH. The mixture is stirred for 5 hours at 50° C. The solvents are evaporated and water is added to the residue. The product is precipitated at pH 4 by addition of 1N aqueous HCl, filtrated, washed with a minimum of water and dried by azeotropic distillation with toluene. The yellowish solid obtained is used directly in the next step; LC/MS: 202/203 (M+H)+.

Provenance & Evidence