Process for the preparation of aqueous betaine solutions

US5292942A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Rudolf Aigner · Burgkirchen an der Alz, DE
• Guillermo Maier · Landsberg am Lech, DE
• Rainer Muller · Penzberg, DE
• Hubert Seitz · Altötting, DE

Key dates

• Filing date: Apr 2, 1993
• Grant date: Mar 8, 1994
• Expiry date: Apr 2, 2013

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61Q19/10
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

A process is described for the preparation of aqueous solutions of betaines of the formula ##STR1## in which: R.sup.1 is an alkyl radical having 6 to 22 carbon atoms or is a radical of the formula R'CONH(CH.sub.2).sub.z --, in which R' has the meaning of R.sup.1 and z is 2, 3 or 4, R.sup.2 is an alkyl radical having 1 to 4 carbon atoms or is a radical of the formula --(CH.sub.2).sub.m --OH, in which m is 1, 2 or 3, R.sup.3 is an alkyl radical having 1 to 4 carbon atoms or is a radical of said formula --(CH.sub.2).sub.m --OH and y is 1, 2 or 3. The aqueous betaine solutions are prepared by quaternization of the corresponding tertiary amines with an .omega.-halocarboxylic acid and with an alkali metal hydroxide in the aqueous phase. The quaternization is carried out continuously in two or three stirred tanks arranged in a cascade, defined process characteristics being maintained in each tank. Using the novel process, aqueous betaine solutions are obtained in high yield and purity in a simple manner.