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:
Aug. 24, 1993
Filed:
Nov. 21, 1989
Pyong-Nae Son, Akron, OH (US);
Victor L Ledesma, Avon Lake, OH (US);
George Kletecka, Fairview Park, OH (US);
The B. F. Goodrich Company, Akron, OH (US);
Abstract
A process for methylating the N.sup.4 atom of a polysubstituted piperazine or piperazin-2-one ('PSP') is effective despite using a much smaller molar excess of formaldehyde and formic acid than dictated by a conventional Eschweiler-Clarke reaction. Particularly in a complex amine in which the PSP substituent is connected to a triazine ring which in turn may be connected to a N atom of an acyclic polyamine, the molar ratio of NH groups:HCHO:HCOOH is in the range from about 1:1:1 to 1:1.5:1.5, the amount of HCHO and HCOOH being sufficient to methylate at least the >NH groups of said PSP substituent if the complex amine contains terminal --NH groups. The same range of molar ratio is maintained when the total number of NH groups to be methylated includes the terminal --NH groups. The effectiveness of the process is attributed to use of an alkylbenzene solvent in which reaction with only a slight excess of HCHO and HCOOH proceeds apace, and in which solvent the methylated product remains dissolved.