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:
Oct. 01, 2002
Filed:
Oct. 17, 2000
Applicant:
Inventors:
Leone Dall'Asta, Milan, IT;
Umberto Casazza, Turate, IT;
Giovanni Cotticelli, Cernusco sul Naviglio, IT;
Assignee:
Norpharma S.p.A., Milan, IT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ; C07D / ;
U.S. Cl.
CPC ...
C07D / ; C07D / ; C07D / ;
Abstract
There is described a process for the preparation of 5-carboxy phthalide, which comprises adding terephthalic acid to fuming sulfuric acid containing at least 20% of SO , then adding formaldehyde to the mixture, heating the mixture at a temperature of 120-145° C. and isolating 5-carboxyphthalide from the reaction mixture.