Carbon Dioxide → 4-methyl-1H-indazole-5-carboxylic acid

Participants

Reaction Steps

This compound was prepared in a manner similar to the preparation of 88 using commercially available 4-bromo-2,3-dimethylaniline as starting material. After an acylation step, N-(4-bromo-2,3-dimethylphenyl)acetamide was treated with isoamyl nitrite, then 10% aqueous HCl to yield 5-bromo-4-methyl-1H-indazole. 5-bromo-4-methyl-1H-indazole was treated with t-butyl lithium and carbon dioxide to yield 4-methyl-1H-indazole-5-carboxylic acid, which in turn was treated with thiosemicarbazide and polyphosphoric acid to form 5-(4-methyl-1H-indazol-5-yl)-1,3,4-thiadiazol-2-amine. MS (API-ES) m/z (%): 232 (100%, M++1).

Provenance & Evidence