Process for preparing alpha-hydroxycarboxylic esters

US8569539B2 · kind B2 · utility

Assignee

• Evonik Röhm GmbH · DE

Inventors

• Alexander May · Seeheim-Jugenheim, DE
• Bernd Vogel · Wiesbaden, DE
• Hermann Siegert · Weiterstadt, DE
• Jochen Ackermann · Heilbad Heiligenstadt, DE
• Soenke Broecker · Ober-Ramstadt, DE

Key dates

• Filing date: Mar 28, 2007
• Grant date: Oct 29, 2013
• Expiry date: Jun 14, 2028

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/10
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Alpha-hydroxycarboxylic esters are prepared by a continuous process in which alpha-hydroxycarboxamide is reacted with an alcohol in the presence of a catalyst to obtain a product mixture which contains alpha-hydroxycarboxylic ester, ammonia, unconverted alpha-hydroxycarboxamide and alcohol, and catalyst; wherein reactant streams containing an alpha-hydroxycarboxamide, an alcohol and a catalyst are fed into a pressure reactor. The reactant streams are reacted with one another in the pressure reactor at a pressure in the range of 1 bar to 100 bar; and the product mixture is depleted in alcohol and ammonia by distilling off ammonia at a pressure which is constantly kept greater than 1 bar without the aid of additional stripping media. The continuous process can be employed particularly advantageously on the industrial scale.