Production of pyridine-3-sulfonic acid

US5082944A · kind A · utility

Assignee

• Rutgerswerke Aktiengesellschaft · DE

Inventors

• Rolf Losch · Ketsch, DE
• Winfried Orth
• Wolfgang Weiss · Ottobrunn, DE
• Hans W. Kleffner · Battenberg, DE

Key dates

• Filing date: Oct 31, 1990
• Grant date: Jan 21, 1992
• Expiry date: Oct 31, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D213/71
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A method for the production of heavy metal-free pyridine -3-sulfonic acid by oxidation of 3-chloro-pyridine to 3-chloro-pyridine-N-oxide, substitution of the chlorine through a sulfonic acid group, and subsequent reduction to pyridine-3-sulfonic acid. The method can be carried out using raw 3-chloropyridine-N-oxide and direct further reaction of the pyridine-3-sulfonic acid-N-oxide in the presence of Raney nickel in an alkaline solution.