反应详情

The isomeric mixture of 1-benzyl-4-nitroindazole and 2-benzyl-4-nitroindazole obtained by the benzylation of 4-nitroindazole is reduced with hydrazine and Raney nickel in methanol and subsequently heated with excess sodium hydrogen sulphite in water. The 1-benzyl-4-aminoindazole (m.p. 73°-75° C.) thereby remains undissolved. Upon acidifying the solution, 2-benzyl-4-hydroxyindazole precipitates out and is obtained in the form of colorless crystals; m.p. 172°-174° C.