Abstract: The invention provides a process for the isolation of crystalline 1,3-cyclohexanedione from the crude product formed in the catalytic gaseous phase cyclization of 5-oxohexanoic acid. Before or directly after condensation an auxiliary component consisting of at least one compound selected from the group consisting of cyclic hydrocarbons, chlorinated aliphatic hydrocarbons and monoethers is added to the crude product, subsequently the mixture of crude product and auxiliary component is distilled under normal or reduced pressure until the reaction water is removed and the residual content of auxiliary component in the remaining concentrate has attained a defined value, and the precipitated crystalline 1,3-cyclohexanedione is filtered off. Alternatively, the auxiliary component added may be distilled off substantially completely.

Abstract: 8-Oxo-5,6,7,8-tetrahydro-2-quinolone is a novel compound which is prepared by hydrolyzing the hydrochloride of the corresponding 8-chloro compound or the hydrobromide of the corresponding 8-bromo compound to give the corresponding 8-hydroxy compound, and dehydrogenating the latter one.

Abstract: 8-Chloro-5,6,7,8-tetrahydro-2-quinolone and 8-bromo-5,6,7,8-tetrahydro-2-quinolone, the hydrochloride or hydrobromide thereof and their manufacture by reacting 3,4,5,6,7,8-hexahydro-2-quinolone with chlorine or bromine in an inert solvent at 10.degree. to 50.degree. C. with heating of the reaction mixture to 60.degree. to 80.degree. C. after the halogen addition.

Abstract: Cyclohexane-1,3-diones of the formula ##STR1## having up to 24 carbon atoms are prepared in admixture with 6-alkyl-3,4-dihydro-2-pyranones of the formula ##STR2## having up to 24 carbon atoms, in which formulae the radicals R and R' may be identical or different and represent each a hydrogen atom, an alkyl, a cycloalkyl or an aryl group each having up to 12 carbon atoms and the two radicals R' together optionally represent a --(CH.sub.2).sub.3 -group, by passing 4-oxocarboxylic acids of the formula ##STR3## having up to 24 carbon atoms and in which R and R' have the above meaning at a temperature of from 250.degree. to 500.degree. C in the gaseous phase over a dehydration catalyst and the pyranones are converted into cyclohexane-1,3-diones by passing them in the gaseous phase over a dehydration catalyst at a temperature of from 250.degree. to 500.degree. C.

Abstract: A process for the preparation of a mixture of carbon tetrachloride and phosgene in the absence of a catalyst fromA. oxygen-containing carbon-hydrogen compounds orB. oxygen-containing carbon-hydrogen compounds, carbon monoxide, carbon dioxide, or water, in admixture with aromatic, chlorinated aromatic, chlorinated aliphatic, or chlorinated cyclo-aliphatic hydrocarbons,With chlorine at an elevated temperature and pressure.