Abstract: Provided is a method for characterizing a molecule by mass spectrometry, which molecule comprises one or more free amino groups, which method comprises: (a) reacting one or more free amino groups in the molecule with a mass tag reagent comprising a reactive functionality capable of reacting with an amino group, and a tertiary amino group linked to the reactive functionality; and (b) characterizing the molecule by mass spectrometry.

Abstract: Provided is a method for characterising a molecule by mass spectrometry, which molecule comprises one or more free amino groups, which method comprises: (a) reacting one or more free amino groups in the molecule with a mass tag reagent comprising a reactive functionality capable of reacting with an amino group, and a tertiary amino group linked to the reactive functionality; and (b) characterising the molecule by mass spectrometry.

Abstract: The invention relates to a novel method for the production of CNA oligomers and to artificial supramolecular CNA-p-RNA pairing systems and to the use thereof, especially in biotechnological assays.

Abstract: The compounds of the formula I or Ia ##STR1## in which R.sup.1 is alkyl, aryl, alkoxy, alkenyl, arylalkyl, alkylaryl, aryloxy, fluoroalkyl, halogenoaryl, alkynyl, trialkylsilyl or a heteroaromatic radical,R.sup.2, R.sup.3 and R.sup.4, in addition to hydrogen, have the meanings given under R.sup.1 andR.sup.5 is hydrogen, alkyl, fluoroalkyl or alkenyl, can be obtained in a one-stage process by reaction of a compound II ##STR2## with (substituted) cyclopentadiene in the presence of a base. The compounds I and Ia are suitable as ligands for metallocene complexes which are used as catalysts in olefin polymerization.

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: 1-Hydroxy-2-pyridones of the formula I ##STR1## in which R.sup.1 =an organic radical andR.sup.2 =H or an organic radical,are prepared by reacting a pyrone of the formula II ##STR2## in which R.sup.1 and R.sup.2 have the same meaning as in formula I, with a hydroxylammonium salt in the presence of at least one alkali metal carbonate and/or hydrogen carbonate.The compounds of the formula I have a biological activity--in particular an antibacterial and antimycotic activity.

Abstract: 6-Methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is prepared by cylcizing acetoacetamide-N-sulfonic acid or its salts with an at least approximately equimolar amount of SO.sub.3 in the presence of a water-immiscible, inert organic solvent and, if appropriate, also an inert, inorganic solvent. In the event that an equimolar amount of SO.sub.3 is employed, working up is effected by adding aqueous sulfuric acid when the cyclization reaction is complete; in the event that the amount of SO.sub.3 employed is more than equimolar, the 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide obtained in the form of the SO.sub.3 -adduct is hydrolyzed by adding water or ice, whereby sulfuric acid is formed from the SO.sub.3 combined in the SO.sub.3 -adduct.The inert, organic solvent is then removed from the resulting multi-phase mixture by distillation, and the 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide is obtained in a pure form from the remaining aqueous sulfuric acid phase by crystallization.

Abstract: The non-toxic salts of 6-methyl-3,4-dihydro-1,2,3-oxothiazin-4-one 2,2-dioxide are prepared by cyclizing acetoacetamide-N-sulfonic acid or its salts with an at least approximately equimolar amount of SO3 in the presence of a water-immiscible, inert organic solvent and, if appropriate, also an inert inorganic solvent, hydrolyzing the 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide obtained in the form of the SO3-adduct after the cyclization reaction, in the event that the amount of SO3 employed is more than equimolar, purifying the organic phase (which has separated out) by extraction with a small volume of water or dilute aqueous sulfuric acid, preferably only with water, and isolating, by neutralization with bases, the non-toxic salts of the 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one 2,2-dioxide from the organic phase thus purified.The said salts are obtained in this process in an extremely pure form; they are valuable synthetic sweetening agents. The potassium salt is known as acesulfam (K).

Abstract: New 1-hydroxy-2-pyridones of the general formula I ##STR1## in which R.sup.1, R.sup.2 and R.sup.3, which are identical or different, denote hydrogen or lower alkyl having 1-4 carbon atoms, R.sup.1 and R.sup.3 preferably being hydrogen, and R.sup.2 preferably being methyl,X denotes S or, preferably, O,Y denotes hydrogen or up to 2 halogen atoms, namely chlorine and/or bromine,Z denotes a single bond or the bivalent radicals O, S, --CR.sub.2 -- (R=H or C.sub.1 -C.sub.4 -alkyl) or other 2-valent radicals with 2-10 carbon and, optionally, oxygen and/or sulfur atoms linked to form a chain, it being obligatory when the radicals contain 2 or more oxygen and/or sulfur atoms for the latter to be separated by at least 2 carbon atoms, and it being possible for 2 adjacent carbon atoms also to be linked together by a double bond, and the free valencies of the carbon atoms being saturated by H and/or C.sub.1 -C.sub.

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: Crystalline salts of acetoacetamide-N-sulfofluoride are prepared by reacting amidosulfofluoride H.sub.2 NSO.sub.2 F with diketene in the presence of inorganic bases, preferably alkali metal carbonates and/or hydrogencarbonates, in particular potassium carbonate, in an inert organic solvent.The salts can be further processed with further base, for example with methanolic KOH, into salts of 6-methyl-3,4-dihydro-1,2,3-oxathiazin-4-one-2,2-dioxide; the potassium salt, in particular, is important for use as a sweetener ("Acesulfame").

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.