Abstract: A process for producing cigarette filters comprising a compound containing L-ascorbic acid and having the compound added to an adsorptional filter material in a quantity of 5-200% of the amount of said adsorptional filter.

Abstract: The invention relates to new crown ether derivatives of the general Formula I ##STR1## and a process for the preparation thereof wherein Z.sup.1 is a group of the general Formula ##STR2## R.sub.a and R.sub.b may be the same or different and R.sub.a represents an alkyl group having 1-4 carbon atoms and R.sub.b is an alkyl group having 1-20 carbon atoms.The new crown ethers are useful in the preparation of ion-selective electrodes having a long lifetime.

Abstract: New crown ether derivatives of formula (I) ##STR1## wherein R stands for hydrogen or C.sub.1-4 alkyln stands for 1,2,X stands for oxygen, sulphur or a NH-groupY represents hydrogen or nitroZ represents a chemical bond, --CH.sub.2 --, --(CH.sub.2).sub.2-4 --, --CH.sub.2 OCH.sub.2 --, --CH.sub.2 SCH.sub.2 --, ##STR2## or a group of the formula ##STR3## suitable for forming cation complexes, process for the preparation thereof and alkali or alkali earth metal ion-selective membrane electrodes containing said compounds are described.

Abstract: Compounds of the formula I ##STR1## or pharmaceutically acceptable salts, hydrates, stereoisomers, optically active isomers, geometrical isomers or tautomeric forms thereof are disclosedwhereinR is hydrogen or lower alkylR.sup.1 is hydrogen, lower alkyl, styryl, or a carboxylic acid; orR and R.sup.1 together form a group of the formula --(CH.dbd.CH).sub.2 -- and in this case the broken line represents a further C--C bond, while in all other cases there is a single bond between positions 6 and 7;R.sup.2 is hydrogen, lower alkyl or hydroxy;R.sup.3 is hydrogen, lower alkyl, aryl, lower alkanoyl, carboxyl or a carboxyl acid derivative or a group of the formula --(CH.sub.2)m--COOH or a derivative thereof formed in the carboxylic group;n=1-3;R.sup.4 is hydrogen, lower alkyl which can be substituted by hydroxy or carboxy; trifluoromethyl, substituted or unsubstituted aryl, phenyl-lower alkyl or substituted or an unsubstituted heterocyclic group;R.sup.

Abstract: The invention relates to a process for the preparation of acyl ureas of formula (I) ##STR1## wherein R.sub.1 and R.sub.2 are the same of different and each is halogen atom, preferably fluorine or chlorine atom, andR.sub.3 is a substituted aryl group.The compounds of the invention can be prepared by reacting an urea of formula (II):R.sub.3 NHCONH.sub.2 (II)wherein R.sub.3 is as defined above, with an acid chloride of formula (III): ##STR2## wherein R.sub.1 and R.sub.2 are as defined above, in an inert organic solvent at a temperature of from 20.degree. C. to 100.degree. C.

Abstract: The invention concerns a new process for the preparation of polyhalogenphenyl carbamates of the formula (I)R.sup.2 -OCONHR.sup.1 (I)whereinR.sup.1 is alkyl, aralkyl or aryl, where the aromatic rings may optionally be substituted; andR.sup.2 is phenyl substituted with three, four or five halogens, through intermediates of the formula (IV)(R.sup.2 --O).sub.2 C.dbd.NR.sup.1 (IV)wherein R.sup.1 and R.sup.2 are as defined above.The compounds of the formula (I) are valuable acylating agents. The intermediates of the formula (IV) are new compounds, which are also encompassed by the invention.

Abstract: Nitrogen bridgehead compounds (pyrido-[1,2-a]-pyrimidine derivatives) which are useful intermediates in the making of known compounds of this class and which themselves possess PG-antagonist, analgesic, antiartheriosclerotic, tranquilizing and like pharmaceutical activity.

Abstract: Antiallergic and particularly antiasthmatic compounds of the formula: ##STR1## of which 9-phenylhydrazono-6-methyl-4-oxo-6,7,8,9-tetrahydro-4H-pyrido(1,2-a)pyrimi dine-3-carboxylic acid is an especially significant example.