The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 04, 1982
Filed:
Nov. 24, 1980
Gerhard Kilpper, Battenberg, DE;
Johannes Grimmer, Ludwigshafen, DE;
Peter Tonne, Neustadt, DE;
Hans C Horn, Lambsheim, DE;
Eckhard Hetzel, Bobenheim-Poxhe, DE;
BASF Aktiengesellschaft, , DE;
Abstract
A process for the continuous preparation of isatoic anhydrides by two-stage reaction of an alkali metal phthalamate and/or alkali metal phthalimidate with an alkali metal hypohalite, the first stage being carried out substantially adiabatically and both stages being carried out at high flow rates, wherein phthalimide and/or phthalamic acid is first dissolved in a certain amount of an alkali metal hydroxide solution, the resulting solution is mixed with a hypohalite and reacted at a particular temperature, acid is then added and the reaction is completed at a particular temperature. The compounds obtainable by the process of the invention are valuable starting materials for the preparation of dyes, crop protection agents and scents.