Abstract: Substituted oxadiazolones of the formula (I) ##STR1## in which R represents optionally substituted alkyl, are obtained in good yields and high purity on reacting in a first step carboxylic acids of the general formula (II)R--COOH (II)with hydrazine hydrate in the presence of a catalyst and an inert diluent at temperatures between 0.degree. C. and 150.degree. C. with elimination of water and removal of said catalyst and reacting the resulting carboxylic hydrazides of the general formula (III)R--CO--NH--NH.sub.2 (III)in a second step with phosgene (COCl.sub.2) at temperatures between 20.degree. C. and 120.degree. C.

Abstract: The present invention relates to new chloropyridinium chlorides of the general formula (I) ##STR1## in which R.sup.1 represents in each case optionally substituted alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkylalkyl, arylalkyl or heteroarylalkyl,R.sup.2 represents optionally substituted alkyl, andR.sup.3 represents hydrogen, halogen or optionally substituted alkyl,to a process for their preparation and to their use for the preparation of chloropyridines.

Abstract: The present invention relates to a process for the preparation of 5-substituted 2-chloropyridines of the formula (I) ##STR1## by reaction of acetenamides of the formula (II) ##STR2## with Vilsmeier reagent, which is prepared by reaction of dialkylformamides of the formula (III) ##STR3## with a chlorinating agent, the excess of which is removed from the reaction mixture by distillation or by addition of dialkylformamide after completion of the reaction of the Vilsmeier reagent with the acetenamide of the formula (II), wherein in the formulae (I)-(III):R represents optionally substituted alkyl or aralkyl,R.sup.1 represents C.sub.1 -C.sub.4 -alkyl or aryl-C.sub.1 -C.sub.4 -alkyl,R.sup.2 and R.sup.3 represent straight-chain, branched or cyclic C.sub.4 -C.sub.8 -alkyl.

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 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 2-dialkylamino-5-methyl-pyridine of the formula ##STR1## in which R is C.sub.1 -C.sub.4 -alkyl.

Abstract: Aryl ethers are chlorinated in the .alpha.-position by a process in which they are metered into a reaction vessel at the same time as chlorine, the reaction being carried out at temperatures in the range from 60.degree. to 150.degree. C.

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: The invention relates to a novel process and novel intermediates for the preparation of 2-amino-5-methylpyridine (I) ##STR1## The process is characterized in that in a first step 3-methyl-pyridine 1-oxide of the formula (II) ##STR2## is reacted with a trialkylamine of the general formula (III)R.sub.3 N (III)in whichR represents alkyl,and with an electrophilic compound, in the presence or absence of a diluent, to give the ammonium salt of the general formula (IV) ##STR3## in which R has the abovementioned meaning andZ.sup..crclbar. represents an anion formed from an electrophilic compound, the compound (IV)is, possibly, isolated as a crude intermediate and, possibly, further purified and then in a second step the ammonium salt of the formula (IV) is reacted with hydrogen bromide, in the presence or absence of a diluent, at temperatures between 150.degree. C. and 300.degree. C.The compound (I) is an intermediate for the preparation of agrochemicals, for example of herbicides.

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: Novel fungicides of the formula ##STR1## in which R.sup.1 represents optionally substituted hydroxyalkyl, optionally substituted hydroxyalkoxyalkyl, optionally substituted heteroarylalkyl or optionally substituted heteroaryl, andR.sup.2 represents optionally substituted alkyl, optionally substituted alkenyl, or alkinyl.Intermediates therefor, wherein R.sup.2 is hydrogen or an alkali metal cation, are also new.

Abstract: A process for the preparation of 3-substituted 4-cyanopyrrole compounds of the formula (I) ##STR1## in which Ar has the meaning given in the description, by reaction in a 1st stage of bromides (II)Ar--Br (II)with acrylonitrile in the presence of a solvent and a suitable reaction auxiliary to give acrylonitrile derivatives (III)Ar--CH.dbd.CH--CN (III)and in a 2nd stage with a phenylsulphonylmethyl isocyanide (IV)Ph--SO.sub.2 --CH.sub.2 --CN (IV)in the presence of a solvent and optionally in the presence of a suitable reaction auxiliary, characterised in that the 1st stage is carried out in the presence of a palladium catalyst and the 2nd stage in the presence of a 1.2- to 1.8-fold molar excess of alkali metal alcoholate or alkali metal hydroxide.

Abstract: A method of combating unwanted vegetation which comprises applying to such vegetation or to a locus from which it is desired to exclude such vegetation, a herbicidally effective amount of a 2-iminopyridine of the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently of one another represent hydrogen, halogen, alkyl, halogenoalkyl, alkoxy, halogenoalkoxy, alkylthio or halogenalkylthio,R.sup.

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: 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: 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: A process for the preparation of 3-trichloromethylpyridine of the formula ##STR1## which comprises reacting 3-methyl-pyridine hydrogen sulphate of the formula ##STR2## with elemental chlorine which exposure to at least one of visible and ultraviolet light at a temperature between about 70.degree. C. and 150.degree. C.

Abstract: A process for the preparation of a chlorinated nicotinaldehyde of the formula ##STR1## in which X is hydrogen or chlorine, which comprises in a first step reacting a 6-alkoxynicotinaldehyde of the formula ##STR2## in which R is alkyl, with a chlorinating agent at a temperature from about 0.degree. C. to 200.degree. C. to form a dichloromethylpyridine of the formula ##STR3## and then in a second step reacting the dichloromethylpyridine with water at a temperature from about 0.degree. C. to 110.degree. C. The products are known intermediates for pharmaceuticals and plant protection agents.

Abstract: Novel herbicides of the formula ##STR1## in which R.sup.1 represents --CH.sub.2 --O--R.sup.5 and at the same time R.sup.2 represents alkyl, orR.sup.2 represents --CH.sub.2 --O--R.sup.5 and at the same time R.sup.1 represents alkyl,R.sup.3 represents hydrogen, alkyl, alkylcarbonyl, alkoxycarbonyl, alkylsulphonyl, alkenyl or alkinyl, or represents optionally substituted aralkyl,R.sup.4 represents aryl or heteroaryl, in each case optionally substituted, andR.sup.5 represents alkyl.