GB1395750A - Indazole compounds - Google Patents

Abstract

1395750 Indazole compounds PECHINEY UGINE KUHLMANN 8 June 1972 [8 June 1971] 26685/72 Heading C2C Novel indazole compounds represented by the resonating structures where one of the substituents R=-NO 2 or -NH 2 and the other of the substituents R= a hydrogen atom, and X=a hydrogen atom or a monovalent cation, e.g. Na, are prepared by diazotizing a compound of formula where one of the substituents R<SP>1</SP>=-NO 2 and the other of the substituents R<SP>1</SP>=a hydrogen atom and X = a hydrogen atom or a monovalent cation by adding to it an aqueous solution of an alkali metal nitrile at temperatures ranging from ambient to 90‹ C., and in the presence of an aliphatic organic acid having up to 5 carbon atoms or a mineral acid and, if necessary, subjecting the cyclized derivative thus obtained to a reduction to convert the nitro group into an amino group 5- or 6-nitro-1,2-dialkylindazolium-3-sulphonates of formula may also be prepared by treating compounds of Formula I where one of thesubstituents R= -NO 2 and the other of the substituents R=a hydrogen atom, with an alkylating agent. The starting materials for the diazotization (Formula II) may be prepared using the following reaction sequences