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:
Feb. 19, 2002
Filed:
Feb. 01, 2001
Frank Ohlbach, Dossenheim, DE;
Johann-Peter Melder, Böhl-Iggelheim, DE;
Karl-Heinz Ross, Grünstadt, DE;
Martin Rudloff, Weisenheim, DE;
Jörg Liebe, Tokyo, JP;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
N-Methyl-2-pyrrolidone (NMP) is prepared by preparing a mixture comprising monomethylamine, dimethylamine and trimethylamine and ammonia in a first process step by reacting ammonia with methanol at elevated temperature in the presence of a catalyst, separating 10 off the ammonia, reacting the mixture comprising the methylamines with gamma-butyrolactone (&ggr;-BL), in a molar ratio of monomethylamine to &ggr;-BL of at least 1 in a second process step at elevated temperature and superatmospheric pressure, separating NMP and unreacted methylamines from the reaction product and returning unreacted methylamines to the first process step for reaction with methanol and ammonia.