Method for producing aqueous ortho-phthalaldehyde solutions
AssigneeDSM Fine Chemicals Austria NFG GmbH & Co KG
InventorsKarlheinz Giselbrecht, Wolfgang Hillisch
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Abstract
A method for producing aqueous ortho-phthalaldehyde solutions which comprises introducing an acetal of the o-phthalaldehyde into water and subsequently setting a pH <7 by adding an acid, whereupon, then at a temperature between 10° C. and 90° C., the acetal is converted into the o-phthalaldehyde by eliminating the corresponding alcohol, and also use of OPA acetals for producing these solutions.
Claims12
A method for producing an aqueous ortho-phthalaldehyde solution which comprises the steps of:
- (a) forming a precursor solution by introducing an acetal of the o-phthalaldehyde into water,
- (b) acidifying the precursor solution to a pH <7 by adding an acid to the precursor solution,
- (c) forming an aqueous ortho-phthalaldehyde solution consisting of ortho-phthalaldehyde, water and the eliminated corresponding alcohol by bringing the acidified precursor solution obtained according to step (b) to a temperature between 10° C. and 90° C. to thereby convert the acetal into o-phthalaldehyde by eliminating the corresponding alcohol, and
- (d) retaining the corresponding alcohol eliminated according to step (c) in the aqueous ortho-phthalaldehyde solution so as to aid in the dissolution of the converted o-phthalaldehyde therein.
An aqueous ortho-phthalaldehyde solution which consists of o-phthalaldehyde, water and a corresponding alcohol eliminated by an acidified reaction of an acetal of the o-phthalaldehyde.
Dependencies are inferred from the claim text.