Sodium Carbonate → 6-hydroxy-1H-indazole

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of 6-aminoindazole (20 mmol) in concentrated HCl (6 mL) at 0° C. was added a solution of NaNO2 (22 mmol) in water (12 mL) in portions. During the addition, the temperature of the reaction mixture was maintained at 0-5° C., and the stirring continued for additional 45 min. The contents were then added into a flask containing 1% aqueous HCl (200 mL), and heated at 100° C. The reaction mixture was then stirred at 100° C. for 5 h. The contents were cooled to RT, neutralized to pH 7 using 5% aqueous Na2CO3, and extracted with EtOAc (2×70 mL). Combined organic layers were washed with brine and dried over anhydrous Na2SO4. Removal of solvent under vacuum provided 6-hydroxyindazole as dark brown solid, which was used for further transformation without any purification.

Provenance & Evidence