Recovery and purification of substituted benzenesulfonates

US6720441B2 · kind B2 · utility

Assignee

• Siemens Axiva GmbH & Co. KG · DE

Inventors

• Rainald Forbert · Flörsheim, DE
• Thomas Diehl · Frankfurt, DE

Key dates

• Filing date: May 24, 2002
• Grant date: Apr 13, 2004
• Expiry date: May 24, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C303/44
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for recovering and purifying substituted benzenesulfonates, by neutralizing a mixture including at least one substituted benzenesulfonate, or at least one corresponding substituted benzenesulfonic acid, and sulfur trioxide, sulfuric acid and/or hydrogen chloride in free or bound form, in an aqueous phase using an alkali metal hydroxide, and purifying it in this aqueous phase, and by subsequently separating the substituted benzenesulfonate(s) from this aqueous phase. The mixture is comminuted into particles having a Sauter mean diameter in the range from 1 &mgr;m to 2 cm, either before or during introduction into this aqueous phase.