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:
Apr. 06, 1976
Filed:
Aug. 16, 1974
Philip Hotchkiss Moss, Austin, TX (US);
Jefferson Chemical Company, Inc., Houston, TX (US);
Abstract
A process for the preparation of 1-methylpiperazine and 1,4-dimethylpiperazine as co-products is disclosed which provides a crude reaction product free of piperazine impurity. The process of the invention comprises mixing and reacting formaldehyde and piperazine at a molar ratio of more than 1.3 to less than about 2.0 and then hydrogenating the resulting reaction product carried in methanol as a major solvent in liquid phase at a temperature of about 60.degree.-130.degree.C. in the presence of a nickel or cobalt hydrogenation catalyst. The crude hydrogenated reaction product is free from piperazine impurity from which 1-methylpiperazine and 1,4-dimethylpiperazine can be readily separated in substantially pure form such as by simple fractional distillation.