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

US3968107A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Karl Clauss · Hofheim, DE
• Erwin Schmidt · Baltmannsweiler, DE
• Hartmut Pietsch · Bad Homburg vor der Höhe, DE
• Harald Jensen

Key dates

• Filing date: Jul 16, 1975
• Grant date: Jul 6, 1976
• Expiry date: Jul 16, 1995

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 and the nontoxic salts thereof are prepared by reacting acetoacetic acid with fluorosulfonyl isocyanate at a temperature of from -20.degree.C to +50.degree.C in the presence of from 0.5 to 2 moles, calculated on the FSI used, of an alkali methal fluoride or a tertiary amine of the formula EQU N(R.sub.1)(R.sub.2)(R.sub.3) in which R.sub.1, R.sub.2, R.sub.3 represent identical or different alkyl radicals having from 1 to 10 carbon atoms, two of the radicals R.sub.1 to R.sub.3 optionally form together an alkylene radical having from 4 to 5 carbon atoms which may contain N, O, or S as hetero atom, or one of the radicals R.sub.1 to R.sub.3 represents a phenyl radical, or of pyridine or quinoline, or of a mixture of the aforesaid compounds, and transforming the salt of acetoacetamide-N-sulfofluoride obtained into the oxathiazinone salt or the free oxathiazinone by a treatment with aqueous and/or alcoholic bases.