Process for the preparation of 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide

US4876341A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Joachim Schutz · Hofheim, DE
• Otto E. Schweikert · Kelkheim, DE

Key dates

• Filing date: Aug 2, 1988
• Grant date: Oct 24, 1989
• Expiry date: Aug 2, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D291/06
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Acetoacetamide-N-sulfonic acid and its salts are cyclized with at least approximately the equimolar amount of SO.sub.3 in short times, preferably in special apparatus, to give 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide. In the case where more than the equimolar amount of SO.sub.3 is used, the latter compound is produced as an SO.sub.3 adduct which then needs to be hydrolyzed; the hydrolysis also takes place in short times and, particularly advantageously, in apparatus of the same type as for the cyclization. The non-toxic salts, especially the potassium salt - of 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide are valuable synthetic sweeteners.