Process for isolating dinitronaphthalenes
AssigneeBayer Aktiengesellschaft
InventorsHeinz Ulrich Blank, Friedrich Durholz, Guido Skipka
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Abstract
1,5- AND 1,8-DINITRONAPHTHALENES ARE ISOLATED FROM MIXTURES OF ISOMETRIC DINITRONAPHTHALENES AT LEAST CONTAINING THE SAME. The mixture of isomers is treated successively with a more polar solvent and a less polar aromatic solvent for dinitronaphthalenes thereby dissolving the mixture of isomers except for 1,5-dinitronaphthalenes which remains largely undissolved in the more polar solvent. The residual mixture of isomers is subsequently treated, after removal of the more polar solvent, with a less polar aromatic solvent at elevated temperatures in which 1,8-dinitronaphthalenes remains as a largely insoluble residue.
Claims16
Process for isolating 1,5- and 1,8-dinitronaphthalene from mixtures of isomeric dinitronaphthalenes at least containing the same which comprises treating the mixture of isomers successively with a more polar solvent and a less polar aromatic solvent for dinitronaphtalenes thereby dissolving the mixture of isomers except for 1,5-dinitronaphthalene which remains largely undissolved in the more polar solvent, and subsequently treating the residual mixture of isomers, after removal of the more polar solvent, with a less polar aromatic solvent at elevated temperature in which 1,8-dinitronaphthalene remains as a largely insoluble residue.
Dependencies are inferred from the claim text.