High purity process for the preparation of 4,6-diamino-1,3-benzenediol

Abstract

High purity 4,6-dinitro-1,3-benzenediol is prepared by (a) contacting a 1,2,3-trihalobenzene with a nitrating agent and an acid under reaction conditions such that a 1,2,3-trihalo-4,6-dinitrobenzene is produced, (b) contacting the 1,2,3-trihalo-4,6-dinitrobenzene prepared in (a) with an alkanol and a base under reaction conditions such that as 4,6-dinitro-2-halo-1,3-benzendiol is produced, and (c) contacting the 4,6-dinitro-2-halo-1,3-benzenediol prepared in (b) with a hydrogenating agent in the presence of a solvent and a catalyst under reaction conditions such that a 4,6-diamino-1,3-benzendiol is produced. This 4,6-diamino-1,3-benzene diol is useful in the preparation of high molecular weight polybenzoxazoles.

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