Preparation of tert-butyl esters of aliphatic carboxylic acids

US10023520B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Catharina Horstmann · Ludwigshafen, DE
• Claus Hechler · Mannheim, DE
• Gregor Grackiewicz · Ludwigshafen am Rhein, DE
• Bernd Schall · Ludwigshafen am Rhein, DE

Key dates

• Filing date: Mar 31, 2016
• Grant date: Jul 17, 2018
• Expiry date: Apr 27, 2036

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C67/62
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for continuously preparing the tert-butyl ester of an aliphatic C1-C4 carboxylic acid comprises: a) the reaction of an aliphatic C1-C4 carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture (G1); b) the partial evaporation of the esterification mixture (G1), giving a liquid first high boiler phase (SPh1) comprising the acidic catalyst, and a first vapor (B1) comprising tert-butyl ester; c) the fractional condensation of the first vapor (B1) by partially condensing the first vapor (B1) at a first pressure and a first temperature and obtaining a first condensate (K1), partially condensing the uncondensed second vapor (B2) at a second pressure and a second temperature and obtaining a second condensate (K2), the first temperature being 0 to 45° C. below the condensation temperature of the tert-butyl ester at the first pressure and the second temperature being 45 to 80° C. below the condensation temperature of the tert-butyl ester at the second pressure, with the proviso that the second temperature is at least 5° C. below the first temperature; and d) the combination of the first condensate (K1) and the second condensate (K2) and…