Process for the preparation of 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide and its non-toxic salts

US4695629A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Karl Clauss · Hofheim, DE
• Adolf Linkies · Frankfurt, DE
• Dieter Reuschling · Rockenberg, DE

Key dates

• Filing date: Jun 3, 1986
• Grant date: Sep 22, 1987
• Expiry date: Jun 3, 2006

Classification

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

Abstract

6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared by PA1 (a) reacting, in an inert organic solvent, a salt of sulfamic acid, which is at least partially soluble therein, with at least approximately the equimolar amount of an acetoacetylating agent, in the presence of an amine or phosphine catalyst, and by cyclizing the acetoacetamide-N-sulfonate which is formed in this reaction, or the free sulfonic acid, PA1 (b) by the action of at least approximately the equimolar amount of SO.sub.3, where appropriate in an inert inorganic or organic solvent, to give 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide, which is produced in the form of the acid in this reaction; it is possible, if desired, to obtain from the acid form PA1 (c) the appropriate salts by neutralization with bases. The non-toxic salts - in particular the potassium salt - are valuable synthetic sweeteners.