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:
Jan. 25, 2000
Filed:
May. 18, 1998
U.S. Bioscience, Inc., Conshohocken, PA (US);
Abstract
The present invention provides for thermally stable forms of 2,4-diamino-5-methyl-6-[(3,4,5-trimethoxyanilino)methyl] quinazoline, or trimetrexate. A crystalline 2,4-diamino-5-methyl-6-[(3,4,5-trimethoxyanilino)methyl] quinazoline monohydrate, or trimetrexate monohydrate, belonging to the space group P1(#2) and having a triclinic cell with dimensions of about a=7.699 .ANG., b=9.606 .ANG. and c=13.012 .ANG. is disclosed. A novel Schiff base compound, 2,4-diamino-5-methyl-6-[(3,4,5-trimethoxyphenylimino)-methinyl]quinazoline , is also disclosed. The present invention further provides novel methods of producing stable trimetrexate free base compounds, including crystalline trimetrexate monohydrate. The crystalline monohydrate form provides increased stability over the anhydrous form.