Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared bya) reacting, 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,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 formc) the appropriate salts by neutralization with bases.The non-toxic salts-- in particular the potassium salt-- are valuable synthetic sweeteners.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared bya) 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,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 formc) the appropriate salts by neutralization with bases. The non-toxic salts--in particular the potassium salt--are valuable synthetic sweeteners.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared by(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,(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(c) the appropriate salts by neutralization with bases. The non-toxic salts - in particular the potassium salt - are valuable synthetic sweeteners.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared by reaction of acetoacetamide with at least approximately twice the molar amount of SO.sub.3 per mole of acetoacetamide, if appropriate in an inert inorganic or organic solvent. Relevant salts can be obtained, using bases, from the product which results in the form of the acid.The non-toxic salts, in particular the potassium salt, are valuable synthetic sweeteners.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide and its non-toxic salts are prepared by reacting acetoacetamide with an S-O compound of the formula IFSO.sub.2 Y (I)wherein Y.dbd.F, Cl, --OSO.sub.2 F or --OSO.sub.2 Cl, preferably only F,in the presence of bases.The non-toxic salts--especially the potassium salt--are valuable synthetic sweeteners.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared by(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,(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(c) the appropriate salts by neutralization with bases.The non-toxic salts--in particular the potassium salt--are valuable synthetic sweeteners.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared by reaction of acetoacetamide with at least approximately twice the molar amount of SO.sub.3 per mole of acetoacetamide, if appropriate in an inert inorganic or organic solvent. Relevant salts can be obtained, using bases, from the product which results in the form of the acid.The non-toxic salts, in particular the potassium salt, are valuable synthetic sweeteners.

Abstract: Process for preparing acetoacetamide-N-sulfofluoride by reacting amidosulfofluoride at a temperature of from 50.degree. to 100.degree. C with diketene, optionally in the presence of inert solvents or diluents.

Abstract: 3-Sulfohalides of 6-methyl-2H-1,3-oxazin-2,4(3H)-dione of the formula I ##STR1## in which X represents fluorine or chlorine are prepared by reacting fluorosulfonyl isocyanate or chlorosulfonyl isocyanate, at a temperature of from -35.degree. to +70.degree. C, optionally in the presence of an inert solvent, with diketene, acetoacetyl fluoride, acetoacetyl chloride, acetoacetic acid or an isopropenyl ester of the formula CH.sub.2 =C(OOCR)-CH.sub.3 in which R represents an alkyl radical having from 1 to 4 carbon atoms, a substituted or unsubstituted phenyl or benzyl radical.

Abstract: Compounds of the formula ##SPC1##In which R represents an alkyl radical having from 1 to 4 carbon atoms and Hal stands for fluorine or chlorine are prepared by reacting at a temperature of from -40.degree. to +20.degree. C an i-propenylalkanoic acid ester of the formula ##EQU1## with an isocyanate of the formulaO=C=N--SO.sub.2 Hal (V)in which R and Hal have the same meaning as above, and isolating the compound of formula III.

Abstract: The potassium salt practically free of fluoride of 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one-2,2-dioxide is prepared by cyclization of acetoacetamide-N-sulfofluoride with at least two moles potassium hydroxide, potassium methylate or a mixture of potassium hydroxide and potassium methylate per mole of sulfofluoride in methanol as solvent containing less than 50 % by weight of water at a temperature of from -20.degree. to +60.degree.C and separating the crystalline potassium salt of the oxathiazinone dioxide from the reaction solution. The compound obtained has a pure sweet taste.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one-2,2-dioxide or the nontoxic salts thereof is prepared by reacting 6-methyl-2,3-dihydro-1,3-oxazin-2,4-dione-3-sulfo-fluoride of the formula ##EQU1## with at least 1 mole water per mole of fluoride to obtain acetoacetamide-N-sulfo-fluoride with splitting off of CO.sub.2, treating the acetoacetamide-N-sulfofluoride with an aqueous and/or alcoholic base and isolating the oxathiazinone or the salts thereof.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one-2,2-dioxide and the nontoxic salts thereof are prepared by reacting acetone and fluorosulfonyl isocyanate in a molar proportion of from 14:1 to 150:1 at a temperature of from 0.degree. to 60.degree.C, distilling off the excess acetone from the reaction mixture with acetoacetamide-N-sulfofluoride and bringing about cyclization by a treatment with bases at a pH of from 5 to 12. The oxathiazinone derivatives are used as sweeteners.

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 formulaN(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.