3-Amino-1H-indazole-6-carbonitrile → 1H-indazole-6-carbonitrile

Participants

Reaction Steps

A solution of sodium nitrite (218 mg, 3.16 mmol) in water (1 mL) was added dropwise over 2 min to a stirred suspension of 3-amino-6-cyanoindazole (250 mg, 1.58 mmol) in water (1 mL) and acetic acid (2 mL) at 0° C. The resulting thick suspension was warmed to rt. After 16 h the mixture was cooled to 0° C. and the solids were collected by filtration, washing with cold water. The solids were suspended in 0.1 M HCl (4 mL), DME (3 mL) was added and the resulting mixture was stirred and heated to 80° C. for 1.5 h. The reaction was cooled and concentrated to ⅓ the volume. The residue was neutralised with sodium bicarbonate and extracted with ethyl acetate. The ethyl acetate layer was washed with water and brine, dried (Na2SO4) and evaporated in vacuo. The residue was purified by chromatography on silica (5:1 chloroform/ethyl acetate) to give the title compound as a yellow solid:

Provenance & Evidence