Abstract: A method of stabilizing N-vinylformamide, which may contain customary polymerization inhibitors, against polymerization during storage or transport, comprises adding to the N-vinylformamide monomers of the general formula ##STR1## where R+H, CH.sub.3 ##STR2## R.sup.2 +C.sub.1 -C.sub.4 -alkyl, as stabilizer in amounts of from 1 to 99 .degree.6 by weight, based on the mixture.

Abstract: 1-Nitroanthraquinone-2-carboxylic acids of the general formula I ##STR1## where X is hydrogen, chlorine or bromine, are prepared by oxidizing a 1-nitro-2-methylanthraquinone of the general formula II ##STR2## with nitric acid in an organic reaction medium.

Abstract: Nitrobenzoic acids I ##STR1## (X.sup.1, X.sup.2 =fluorine, chlorine, bromine, hydrogen or nitro) are prepared by oxidizing the corresponding nitrotoluene II ##STR2## with nitric acid in the presence of sulfuric acid and vanadium(V) compounds, and anthranilic acids III ##STR3## (Y.sup.1, Y.sup.2 =fluorine, chlorine, bromine, hydrogen or amino) are prepared from the nitrobenzoic acids I by reduction.

Abstract: A process for the preparation of 4-sulfonated anthranilic acids by sulfonation of ortho-nitrotoluenes with chlorosulfonic acid or oleum followed by oxidation of the methyl group and, finally, reduction of the nitro group.

Abstract: 3-Methylquinoline-8-carboxylic acid I ##STR1## and derivatives thereof are prepared by reacting o-toluidine II or a derivative thereof ##STR2## with methacrolein II ##STR3## in 70-90% strength by weight sulfuric acid in the presence of iodine or of an iodine compound, and oxidizing the resulting 3,8-dimethylquinoline IV or a derivative thereof ##STR4## with nitric acid in a solution containing sulfuric acid, in the presence of vanadium ions, by a process in which, in the sulfuric acid-containing reaction solution of the 3,8-dimethylquinoline IV, the byproducts of the reaction are first decomposed by oxidation, the resulting 3,8-dimethylquinoline solution is concentrated by distillation and the 3,8-dimethylquinoline is then oxidized in situ with nitric acid to give the 3-methylquinoline-carboxylic acid.

Abstract: 7-Chloroquinoline-8-carboxylic acids of the formula (I) ##STR1## where R is hydrogen, chlorine or methyl, are prepared by direct oxidation of the corresponding 8-methylqunoline compound with nitric acid or nitrogen oxide in the presence of sulfuric acid and a heavy metal catalyst.

Abstract: A process for the preparation of 8-bromomethyl-3-methylquinoline compounds of the formula I ##STR1## where one or both substituents X are chlorine and, where relevant, the other substituent X is hydrogen, by bromination of the corresponding 8-methylquinoline compound in the presence of a 2-phase mixture of a solvent stable to bromination and of, preferably, buffered water.

Abstract: A process for the preparation of 8-bromomethyl-3-methylquinoline compounds of the formula I ##STR1## where one of both substituents X are chlorine and, where relevant, the other substituent X is hydrogen, by bromination of the corresponding 8-methylquinoline compound in the presence of a 2-phase mixture of a solvent stable to bromination and of, preferably, buffered water.