Process for the preparation of purified phthalimidoalkanecarboxylic acids
AssigneeHoechst Aktiengesellschaft
InventorFrank Jaekel
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Abstract
Process for the preparation of purified phthalimidoalkanecarboxylic acids The present invention relates to a process for the preparation of purified phthalimidoalkanecarboxylic acids which are contaminated with phthalic acid, lactam and/or water, including the following measures: a) fusing the contaminated phthalimidoalkanecarboxylic acid, b) holding the melt for a period and at a temperature sufficient for the impurities to have substantially departed from the melt and c) cooling the purified product melt.
Claims21
A process for the preparation of purified phthalimidoalkanecarboxylic acids from previously prepared, contaminated phthalimidoalkanecarboxylic acids which are contaminated with phthalic acid, lactam, water or a mixture thereof, including the following steps:
- a) fusing the previously prepared, contaminated phthalimidoalkanecarboxylic acid to obtain a melt,
- b) holding the melt for a period and at a temperature sufficient to cause the phthalic acid, lactam, water, or mixture thereof to substantially separate from the melt, and
- c) cooling the resulting purified product melt.
Dependencies are inferred from the claim text.