Abstract: Compounds of the formula ##STR1## which are intermediates in the preparation of hydantoin aldose reductase inhibitors and methods of preparing these intermediates.

Abstract: An improved process for the preparation of 2,3,5,6-tetrachloropyridine of the formula ##STR1## consists in that 3,3,5-trichloroglutarimide of the formule ##STR2## is reacted either a. with phosphorus trichloride or phosphorus oxytrichloride or mixtures thereof in the presence from the start of catalytic amounts of hydrogen chloride, followed by a conversion of polyphosphorous compounds formed into phosphorus oxytrichloride by supplying chlorine, optionally only after supplying further phosphorus trichloride, orb. with phosphorus trichloride and chlorine, optionally in the presence of phosphorus oxytrichloride as a solvent, followed by a dehydrochlorination of the reaction mixture and finally conversion of polyphosphorus compounds formed into phosphorus oxytrichloride by supplying chlorine, optionally only after supplying further phosphorus trichloride.Improved yields of a purer product are obtained.

Abstract: Novel 2-(2,2-difluorocyclopropyl)-acetic acid derivatives of formula I ##STR1## wherein A is oxygen or --NR.sub.1 --,B is C.sub.2 -C.sub.6 alkylene,D is oxygen, sulfur or --O--CH.sub.2 --,E is phenyl; phenyl substituted by from one to three substituents selected from the group halogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.3 haloalkyl and C.sub.1 -C.sub.4 alkoxy; a five-membered aromatic heterocycle having from one to three hetero atoms selected from the group nitrogen, oxygen and sulfur; a five-membered aromatic heterocycle having from one to three hetero atoms selected from the group nitrogen, oxygen and sulfur that is substituted by one or two substituents selected from the group halogen, C.sub.1 -C.sub.4 alkyl and C.sub.1 -C.sub.3 haloalkyl; a six-membered aromatic heterocycle having from one to three nitrogen atoms; or a six-membered aromatic heterocycle having from one to three nitrogen atoms that is substituted by one or two substituents selected from the group halogen, C.sub.1 -C.sub.4 alkyl and C.

Abstract: Chlorinated aromatic compounds are dechlorinated in a simple and inexpensive manner by heating them to 300.degree. to 450.degree. C. in a salt melt in the presence of water and/or water vapor and carbon.

Abstract: The reaction of nitrogen dioxide with hydrogen chloride to give nitrosyl chloride and nitric acid can be advantageously carried out in cocurrent in a reactor in such a way that the reactants are introduced at the bottom and the nitrosyl chloride is taken off at the top and the nitric acid is taken off at the bottom of the reactor.

Abstract: A process for preparing polycyclic aromatic compounds by cross-coupling aromatic boronic acids with aromatic halogen compounds or perfluoroalkylsulfonates in the presence of metallic palladium, if desired applied to a support material, as catalyst, wherein the coupling is carried out in the presence of a ligand and a base. The process of the invention allows the yield of polycyclic aromatic compounds to be significantly increased in comparison with processes not using a ligand and thus allows a yield optimum for the Pd(0)-catalyzed cross-coupling of aromatic boronic acids with aromatic halogen compounds to be achieved.

Abstract: A process for the preparation of a chloropyridine of the formula ##STR1## which comprises reacting an enamide of the formula ##STR2## with a chlorinating agent in the presence of a di-substituted formamide ##STR3## in which R.sup.4 and R.sup.5 each individually is alkyl or cycloalkyl or together are alkanediyl, at a temperature between about -30.degree. C. and 100.degree. C., thereby to produce a compound of the formula ##STR4## and subjecting said compound to thermal cleavage. Compounds I are novel. Compounds IV are known intermediates for agrochemicals and pharmaceuticals.

Abstract: A method for producing 2-chloropyridine and 2,6-dichloropyridine by the steps of mixing vaporized chlorine and vaporized water to obtain dilute chlorine; introducing the dilute chlorine and vaporized pyridine into a reactor; and reacting the vaporized pyridine with the dilute chlorine in a gas phase under ultraviolet rays irradiation. By the method, 2-chloropyridine and 2,6-dichloropyridine can be produced in high yields. The present invention is also directed to a method for separating 2,6-dichloropyridine from a mixture containing 2,6-dichloropyridine, 2-chloropyridine and pyridine by the step of carrying out distillation of the mixture containing 2,6-dichloropyridine, 2-chloropyridine and pyridine in the presence of water while adding sulfuric acid to a distillation column. Highly purified 2,6-dichloropyridine can be separated by the method.

Abstract: The cyclohexadiene derivatives are prepared by reaction of cyclohexanones with amines and subsequent dehydration. The compounds are suitable as active compounds in medicaments on account of their property of being selective modulators of calcium channel-dependent potassium channels.

Abstract: A process for the preparation of a 2-halogeno-pyridine of the formula ##STR1## in which X represents halogen andY represents halogen, nitro, formyl, cyano, carboxyl, carbamoyl, alkyl, halogenoalkyl, alkoxyalkyl, dialkoxyalkyl, alkoxycarbonyl, alkylaminocarbonyl or dialkylaminocarbonyl,which comprises in a first stage reacting a pyridine 1-oxide of the formula ##STR2## with an organic nitrogen base A and an electrophilic compound, optionally in the presence of a diluent, to produce a compound of the formula ##STR3## in which A represents the radical of an organic nitrogen base, andZ.sup.- represents an anion formed from an electrophilic compound,optionally isolating and optionally purifying the compound of the formula (III).

Abstract: A method for halogenating an aromatic compound, which comprises reacting the aromatic compound of the formula (I): ##STR1## wherein X is a hydroxyl group, an amino group or an acylamino group, each of Z.sub.1 and Z.sub.2 is a hydrogen atom or a halogen atom, one of R and Y is a hydrogen atom and the other is a nitro group, a cyano group or a trifluoromethyl group, and Q is a nitrogen atom or --C(T).dbd. (wherein T is a hydrogen atom, a halogen atom, a nitro group, a cyano group or a trifluoromethyl group), with a halogenating agent to obtain a 3-halogenoaromatic compound of the formula (II): ##STR2## wherein one of R' and Y' is a halogen atom and the other is a nitro group, a cyano group or a trifluoromethyl group, and X, Z.sub.1, Z.sub.2 and Q are as defined above.

Abstract: A process for the selective chlorination of pyridine, a lower alkyl pyridine or 3-cyanopyridine includes passing the pyridine compound, chlorine and an inert gas through a two stage reaction. In a first reaction zone, these materials are subjected to a hot spot controlled at a temperature of about 350.degree. to about 500.degree. C. The materials are then subsequently passed through a second reaction zone at a relatively lower temperature, for example below about 340.degree. C.

Abstract: A heterogeneous catalytic chlorination process for making chlorinated aromatic compounds with high para-selectivity. Examples of chlorinated aromatic compounds that can be prepared using the process disclosed in the present invention include those compounds represented by the following formula: ##STR1## wherein R can be a C1-C3 alkyl, floride, chloride, bromide, iodide, or hydroxyl group. The chlorination process utilizes a de-aluminated zeolite which is prepared by H.sub.4 EDTA or Na.sub.4 EDTA extraction of L-type zeolite to reduce the alumina content thereof. The SiO.sub.2 /Al.sub.2 O.sub.3 ratio of the de-aluminated zeolite is preferably between about 9 and about 40. The de-aluminated zeolite can be ion-exchanged with Group IA or IIA metal ions to further improve its para-selectivity.

Abstract: The invention relates to a novel process for the preparation of substituted 2,3-difluoropyridines by reaction of substituted 2,3-halopyridines with fluoride salts in the presence of phase transfer catalysts, preferably in polar aprotic solvents, without removing the resulting substituted 2,3-difluoropyridines continuously from the reaction mixture. The substituted 2,3-difluoropyridines which can be prepared according to the invention are, inter alia, starting materials for the preparation of plant protection agents or pharmaceuticals.

Abstract: The present invention relates to a process for preparing 2,6-dichloropyridine which comprises reacting an organic solvent-free, catalyst-free reaction mixture comprising 2-chloropyridine and chlorine in the presence of a hydrogen chloride scavenger and ultraviolet light, and optionally in the presence of added moisture, at a temperature of between about 90.degree. C. and about 185.degree. C. Also claimed is a method for preventing calcium chloride plugging of the chlorine feed stream and for preventing calcium chloride build-up in the above reaction mixture which comprises adding moisture in the form of water or steam, or a combination thereof, to the reaction mixture prior to, or during, the reaction of said process.

Abstract: A 3-fluoropyridine of the formula (I) ##STR1## in which the symbols have the following meanings: R.sup.1 and R.sup.2, independently of one another, are, for example, H or straight-chain or branched alkyl, A.sup.1, A.sup.2, A.sup.3 and A.sup.4 are identical or different and are, for example, 1,4-phenylene, pyrazine-2,5-diyl or trans-1,4-cyclohexylene, M.sup.1, M.sup.2, M.sup.3 and M.sup.4 are identical or different and are, for example, --O-- or --CO--O--, R.sup.3, R.sup.4, R.sup.6 and R.sup.7, independently of one another are, for example, H or straight-chain or branched alkyl, M.sup.5 is for example, --O--CO-- or a single bond, k, l, m, n, o, p, q and r are zero or one, with the proviso that the sum k+m+p+r is less than 4 and greater than zero, can advantageously be employed as a component in ferroelectric liquid-crystal mixtures.

Abstract: The invention relates to a novel process for preparing chloromethylpyridines of the general formula (I) ##STR1## in which n represents the numbers 0,1,2 or 3 andX represents halogen,by reacting aminomethylpyridines of the general formula (II) ##STR2## with a nitrosating or diazotizing agent in the presence of a diluent and optionally in the presence of hydrogen chloride at temperatures between -20.degree. C. and +50.degree. C. and then working up in a conventional manner.

Abstract: Compounds of the formula ##STR1## wherein R.sup.1 is hydrogen, fluoro, chloro, bromo, nitro, trifluoromethyl, C.sub.1 to C.sub.4 alkoxy, C.sub.1 to C.sub.4 alkylthio or C.sub.1 to C.sub.6 alkyl and R.sup.2 is a group of the formula ##STR2## wherein R.sup.3 is hydrogen or C.sub.1 to C.sub.6 alkyl, R.sup.4 is --CH.dbd.C.sub.2, --CH.sub.2 --YR.sup.5, or --COR.sup.6, R.sup.5 is hydrogen or an acid labile alcohol protecting group, Y is oxygen or sulfur, and R.sup.6 is --NR.sup.7 R.sup.8 or --OR.sup.9 wherein R.sup.7, R.sup.8 and R.sup.9 are independently selected from hydrogen or C.sub.1 to C.sub.6 alkyl, or an alkaline or alkaline earth metal salt thereof, which are intermediates in the preparation of hydantoin aldose reductase inhibitors and methods of preparing these intermediates.

Abstract: A process for the preparation of aromatic compounds of the general formula I,Ar--X Iin which Ar represents an optionally substituted aryl group and X represents a group OH, Cl, Br or CN, by reaction of an aryl diazoniumsalt of the formula II,Ar--N.dbd.N.sup.+ Y.sup.- IIin which Ar is as defined above and Y represents a suitable counterion, with water, hydrogen chloride or a salt thereof, hydrogen bromide or a salt thereof, or a cyanide in the presence of a copper(I)salt, characterized in that the copper(I)salt is a copper(I)salt derived from an hydroxy carboxylic acid.

Abstract: Fluoro-substituted phenyl-cyclohexylacetylenes have the formula: ##STR1## wherein R signifies alkyl, alkoxy, alkenyl or alkenyloxy with 1 or, respectively, 2 to 12 carbon atoms in which one CH.sub.2 group can be replaced by oxygen and/or one or more hydrogen atoms can be replaced by fluorine atoms, with the proviso that two oxygen atoms are not directly adjacent;A.sup.1 represents 1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, trans-1,4-cyclohexylene or trans-1,3-dioxane-2,5-diyl;A.sup.2 signifies trans-1,4-cyclohexylene or 1,4-phenylene which is optionally substituted with fluorine;Z.sup.1 signifies a single covalent bond, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O--, --(CH.sub.2).sub.4 --, --O(CH.sub.2).sub.3 --, --(CH.sub.2).sub.3 O-- or, when ring A.sup.1 represents a saturated ring, also the trans form of --CH.dbd.CH(CH.sub.2).sub.2 -- or --CH.dbd.CHCH.sub.2 O--;Z.sup.2 signifies a single covalent bond, --CH.sub.2 --CH.sub.2 --, --OCH.sub.2 --, --CH.sub.2 O--, --(CH.sub.2).sub.

Abstract: The compounds of the formula I ##STR1## in which Y and Y.sub.1 are each, independently of one another, O, S, NH or N-alkyl, N-cycloalkyl, N-phenyl or N-benzyl, or Y and Y.sub.1 are together N-alkylene-N,R and R.sub.1 are each, independently of one another, H, alkyl, cycloalkyl, aralkyl or aryl,R.sub.2 and R.sub.3 are each, independently of one another, H, or R.sub.2 forms, together with R.sub.6 and the N and C atoms linking them, a 5- or 6-membered ring and R.sub.3 is H, or R.sub.3 forms, together with R.sub.7 and the N and C atoms linking them, a 5- or 6-membered ring and R.sub.2 is H,R.sub.4 and R.sub.5 are each, independently of one another, H, R.sub.4 forms, together with R.sub.8 and the N and C atoms linking them, a 5- or 6-membered ring and R.sub.5 is H, or R.sub.5 forms, together with R.sub.9 and the N and C atoms linking them, a 5- or 6-membered ring and R.sub.4 is H,R.sub.6, R.sub.7, R.sub.8 and R.sub.9 are each, independently of one another, H, alkyl, cycloalkyl, aralkyl or aryl, or R.sub.6 and R.

Abstract: A process for the preparation of isomer-free 2,5-dichloropyridine comprising alkoxylating 2-chloro-pyridine or 2-bromo-pyridine in the presence of a base at elevated temperatures, chlorinating with gaseous chlorine the alkoxylated product at ambient temperatures in an aqueous suspension in the presence of an auxiliary base, a small amount of a catalyst and optionally a small amount of an emulsifier, treating the isomer reaction mixture with a Vielsmeyer-Haack reagent, subjecting 2,5- and 2,3-dichloropyridine mixture to water vapor distillation and crystallizing the crystalline product from an alcohol-water mixture.

Abstract: N-fluoropyridinium salts of the following formula are prepared by reacting a pyridine compound with a Br nsted acid and fluorine, wherein the reaction solvent contains a greater than equimolar amount of the pyridine compound relative to an amount of the Br nsted acid. ##STR1## The method can produce N-fluoropyridinium salts with a high yield.

Abstract: A process for the preparation of a substituted 2-chloropyridine derivatives of the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 represent hydrogen or various other radicals, which comprises reacting a pyridine-1-oxide of the formula ##STR2## with an aromatic carbonyl chloride in the presence of an inert organic solvent and in the presence of an acid acceptor at a temperature between about -20.degree. C. and 200.degree. C.

Abstract: A process for the preparation of a 2-chloro-5-chloro-methyl-pyridine, of the formula (I) ##STR1## comprising reacting a 2-alkoxy-5-alkoxymethylpyridine derivative of the formula (II) ##STR2## in which R.sup.1 represents alkyl, with a chlorinating agent, if appropriate, in the presence of a diluent and if appropriate, in the presence of a reaction auxiliary, at a temperature between 0.degree.C. and 200.degree.C.

Abstract: The invention relates to a method of chlorinating a side chain methyl group of 2-chloro-methylpyridine. The method comprising the steps of:(a) reacting said 2-chloro-methylpyridine with chlorine radical so that hydrogen chloride and/or hydrochloride of 2-chloro-methylpyridine are formed; and (b) neutralizing said hydrogen chloride and/or said hydrochloride of said 2-chloro-methyl-pyridine with a basic solution so as to chlorinating a side chain methyl group of said 2-chloro-methylpyridine.

Abstract: 2,3,5,6-Tetrachloropyridine, and 2,3-dichloro-5-(trichloromethyl)pyridine are prepared by selectively chlorinating polychlorinated .beta.-picolines in the vapor phase between about 250.degree. and 450.degree. C. in the presence of specific Lewis acid halide catalysts on an inorganic support. The gamma position on the pyridine ring is usually not chlorinated in the starting material or reaction products. These compounds are useful intermediates to produce insecticides and herbicides.

Abstract: A process for halogen exchange fluorination or fluoro-denitration of aromatic compounds having at least one replaceable non-fluorine halogen or nitro substituent with an anhydrous substantially molten alkali metal acid fluoride composition wherein the alkali metal is potassium, rubidium or cesium.

Abstract: A method for producing a dichloromethylpyridine of the formula (II): ##STR1## wherein each of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 which are independent of one another, is a hydrogen atom, a halogen atom, an alkoxy group or a phenoxy group which may be substituted, provided that R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are not simultaneously hydrogen atoms, which comprises reacting a trichloromethylpyridine of the formula (I): ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined above, with a reducing agent, wherein:(1) a dialkyl phosphite or a trialkyl phosphite is used as the reducing agent, and the reaction is conducted in the presence of a basic substance and an alcohol solvent, or(2) a trialkyl phosphine or triphenyl phosphine is used as the reducing agent, and the reaction is conducted in the presence of an alcohol solvent.

Abstract: 2-Chloropyridine derivatives of the formula (I) ##STR1## in which R represents hydrogen, C.sub.1 -C.sub.4 -alkyl or halogen andn represents 0 to 4,are obtained in good yields and high purity when a 2-aminopyridine derivative of the formula (II) ##STR2## in which R and n have the above definitions,is reacted with nitrosyl chloride in a hydrogen chloride-saturated aqueous solution at temperatures between -10.degree. C. and +50.degree. C. with simultaneous introduction of hydrogen chloride.

Abstract: The invention relates to a process for the reaction of fluorinated or chlorinated aromatics with electrophiles at the ortho position relative to the fluorine or chlorine atom, characterized in that a strong base is added to a mixture of the fluorinated or chlorinated aromatic and the electrophile.

Abstract: A process for the selective chlorination of pyridine or a lower alkyl pyridine includes passing the pyridine compound, chlorine and an inert gas through a two stage reaction. In a first reaction zone, these materials are subjected to a hot spot controlled at a temperature of about 350.degree. to about 500.degree. C. The materials are then subsequently passed through a second reaction zone at a relatively lower temperature, for example below about 340.degree. C.

Abstract: A process for the preparation of a 2-alkoxy-5-alkoxymethylpyridine derivative of the formula (II) ##STR1## in which R.sup.1 represents alkyl, comprising reacting a 3-dichloromethylpyridine, of the formula III, ##STR2## with an alcohol of the formula R.sup.1 --OH (IV) and with the corresponding alkali metal alkoxide of this alcohol, at a temperature between 0.degree. C. and 150.degree. C.

Abstract: Polychlorodipyridoimidazolium tetrachloroferrate compounds, such as 1,2,3,4,11-pentachloro-8-(trichloromethyl)dipyrido[1,2-a:1',2'-]imidazol-1 0-ium tetrachloroferrate, which are obtained as by-products in the preparation of polychloropyridine and polychloropicoline compounds by chlorination of many chloro(trichloromethyl)pyridine compounds in the presence of ferric chloride catalyst and can be prepared by heating a mixture of a chloro-2-(trichloromethyl)pyridine compound with a 2-chloro-5-(trichloromethyl)pyridine compound, can be converted to pentachloropyridine by chlorination at temperatures above about 230.degree. C. and pressures above about 300 psig (2.17 mPa).

Abstract: Compounds and compositions containing alkylphosphonothioates, for insecticidal control, particularly for use as soil and/or foliar insecticides, having the formula. ##STR1## in which R is C.sub.1 -C.sub.3 alkyl;R.sub.1 is C.sub.4 -C.sub.6 branched alkyl;R.sub.2 is hydrogen, methyl, ethyl, cyano or C.sub.2 -C.sub.4 alkynyl; ##STR2## R.sub.4 is halo, C.sub.1 -C.sub.2 haloalkyl, C.sub.1 -C.sub.4 alkoxy, C.sub.1 -C.sub.4 thioalkyl or mono-or di-C.sub.1 -C.sub.2 alkylamino;n is 1-3; andX is O or S.

Abstract: The invention relates to pyridine derivatives of the formula I ##STR1## wherein R.sup.1, A.sup.1, E.sup.1, n, A.sup.2, Z.sup.2, X and Y have the meaning given in claim 1.

Abstract: In the chlorination of the side chain of an alkylated nitrogen heteroaromatic such as pyridine or pyrimidine by reaction with elemental chlorine, the reaction is effected in acetronitrile as solvent.

Abstract: This invention concerns a process for preparing fluoroalkyl substituted olefins, fluorinated ketones and fluorinated aromatic compounds by the catalyzed reaction of fluoroalkylsilanes with selected fluorinated olefins, acyl fluorides and fluorinated aromatic compounds, respectively.

Abstract: A pyridine derivative of the formula: ##STR1## wherein R.sup.1 is, the same or different, each a hydrogen atom, a halogen atom, a C.sub.1 -C.sub.4 alkyl group, a C.sub.1 -C.sub.4 haloalkyl group, a C.sub.1 -C.sub.3 alkoxy gorup, a C.sub.1 -C.sub.3 haloalkoxy group, a cyano group or a nitro group; R.sup.2 is, the same or different, each a hydrogen atom, a halogen atom or a methyl group; R.sup.3 is a halogen atom or a C.sub.1 -C.sub.3 alkyl group; R.sub.4 is a hydrogen atom or a C.sub.1 -C.sub.3 alkyl group; R.sup.5 is, the same or different, each a halogen atom, a C.sub.1 -C.sub.3 alkyl group, a C.sub.1 -C.sub.3 haloalkyl group, a C.sub.1 -C.sub.3 alkoxy group or a C.sub.1 -C.sub.3 haloalkoxy group; X is an oxygen atom, a sulfur atom, a carbonyl group, a sulfinyl group, a sulfonyl group, an imino group or a methylene group; Y is an oxygen atom or a sulfur atom; l is an integer of 1 to 5; m is an integer of 1 to 3; and n is an integer of 1 to 4, which is useful for control of insect pest.

Abstract: A process for the hydrogenolysis and/or dehydrohalogenation of fluorohalocarbons and/or fluorohalohydrocarbons by reacting the fluorohalocarbons and/or fluorohalohydrocarbons with a source of hydrogen in the presence of a catalyst, the improvement comprising utilizing a rhenium-containing catalyst, which may, optionally, contain at least one Group VIII metal and may, optionally, be supported.

Abstract: The deazauracil containing probes of the invention are able to withstand higher temperatures, thereby allowing unmatched probes and mismatched probes to be washed off at higher hybridization stringency, thereby eliminating background readings and improving ease and accuracy of probe use.

Abstract: A process for the preparation of a 2-chloro-5-chloromethyl-pyridine, of the formula (I) ##STR1## comprising reacting a 2-alkoxy-5-alkoxymethylpyridine derivative of the formula (II) ##STR2## in which R.sup.1 represents alkyl,with a chlorinating agent, is appropriate, in the presence of a diluent and if appropriate, in the presence of a reaction auxiliary, at a temperature between 0.degree. C. and 200.degree. C.

Abstract: A process for preparing 2,6-dichloropyridine, which comprises reacting 2-chloropyridine with chlorine in a liquid phase in the absence of a catalyst at a temperature not lower than 160.degree. C. According to the process, high-purity 2,6-dichloropyridine can be prepared in a high yield with ease.

Abstract: 2-Hydrocarbyl-3,6-dichloropyridines are prepared from dichloromethyl hydrocarbyl ketones and acrylonitrile in a two-step process involving an addition reaction under basic conditions to form intermediate 1,1-dichloro-3-cyanopropyl hydrocarbyl ketones and a subsequent cyclization reaction in the presence of hydrogen chloride. Thus, 3,6-dichloro-2-methylpyridine is prepared from 1,1-dichloro-2-propanone and acrylonitrile by the formation and further reaction of 4,4-dichloro-5-oxo-hexanenitrile. The intermediates and products are novel compounds useful in the preparation of herbicides and nitrification inhibitors.

Abstract: In the preparation of 2-chloro-5-methyl-pyridine of the formula ##STR1## by reacting 3-methyl-pyridine-1-oxide of the formula ##STR2## with a chlorinating agent, the improvement which comprises effecting the reaction in the presence of a chlorinating agent of the formula ##STR3## in which A represents oxygen or the grouping ##STR4## in which R.sup.2 and R.sup.3 individually represent alkyl, cycloalkyl or aryl or together represent alkanediyl or oxaalkanediyl andR.sup.1 represents hydrogen, chlorine, alkyl, cycloalkyl, aryl or the grouping ##STR5## in which R.sup.2 and R.sup.3 have the abovementioned meanings,and where, if R.sup.1 represents aryl, A must represent the grouping ##STR6## in the presence of a basic organic nitrogen compound and in the presence of a diluent at a temperature between about -20.degree. C. and +120.degree. C. The product is known to be useful in the systhesis of pharmaceuticals and insecticides.

Abstract: A process for the preparation of 2-chloro-5-methylpyridine of the formula ##STR1## which comprises reacting 3-methyl-pyridine-1-oxide of the formula ##STR2## with a chlorinating agent of the formula ##STR3## in which R.sup.1 represents alkyl, halogenoalkyl, cycloalkyl, optionally substituted aryl, NR.sup.2 R.sup.3 or OR.sup.4 in whichR.sup.2 and R.sup.3 individually represent alkyl, cycloalkyl or aryl or together represent alkanediyl or oxaalkanediyl andR.sup.4 represents alkyl, cycloalkyl or optionally substituted aryl,in the presence of a basic organic nitrogen compound and in the presence of a diluent at a temperature between about -20.degree. C. and +150.degree. C.

Abstract: Optically active nitrogen-containing heterocycles of the formula I according to claim 1 are suitable as components for ferroelectric liquid crystalline materials.

Abstract: A 3,4-pyridine-dithiol compound having formula (I): ##STR1## wherein X is chlorine or a trifluoromethyl group; and a method of producing the above 3,4-pyridine-dithiol compound having formula (I) by allowing a polyhalogenide pyridine compound having formula (II) to react with a hydrosulfide in a polar organic solvent in the presence of sulfur, and an iron powder or an iron salt: ##STR2## wherein X is chlorine or a trifluoromethyl group.

Abstract: 2-Hydrocarbyl-3,6-dichloropyridines are prepared from dichloromethyl hydrocarbyl ketones and acrylonitrile in a two-step process involving an addition reaction under basic conditions to form intermediate 1,1-dichloro-3-cyanopropyl hydrocarbyl ketones and a subsequent cyclization reaction in the presence of hydrogen chloride. Thus, 3,6-dichloro-2-methylpyridine is prepared from 1,1-dichloro-2-propanone and acrylonitrile by the formation and further reaction of 4,4-dichloro-5-oxo-hexanenitrile. The intermediates and products are novel compounds useful in the preparation of herbicides and nitrification inhibitors.

Abstract: A pyridine-compound is reacted with fluorine together with a .[.Bronsted.]. .Iadd.Bronsted .Iaddend.acid-compound or Lewis acid to form a N-fluoropyridinium salt which is very active to other compounds but is very selective for the preparation of a desired product and this product is very useful for a fluorine-introducing agent which makes it useful for the preparation of fluoro-compounds such as thyroid inhibitor.