Abstract: Process for the selective preparation of meta-chloroanilines.It is carried out by the hydrodechlorination of polychloroanilines or polychloronitrobenzenes with hydrogen, in the liquid phase, under the action of heat, at atmospheric pressure or under pressure, in the presence of a noble metal, in an anhydrous organic medium and in the presence of a Lewis acid.These meta-chloroanilines are intermediates especially for active plant-protection substances.

Abstract: Meta-chlorophenols useful as intermediates in various organic syntheses are prepared by selectively catalytically hydrodechlorinating a polychlorophenol in liquid organic phase and in the presence of a nobel metal catalyst and a Lewis acid, said polychlorophenol bearing chlorine substituents in both the meta- and ortho- and/or para-positions.

Abstract: Meta-chlorophenols useful as intermediates in various organic syntheses are prepared by selectively catalytically hydrodechlorinating a polychlorophenol in liquid phase in an acid solvent medium which is at least partially aqueous and which comprises halide ions, in the presence of a Group VIII noble metal catalyst, said polychlorophenol bearing chlorine substituents in both the meta- and ortho- and/or para-positions.

Abstract: Meta-chlorophenols useful as intermediates in various organic syntheses are prepared by selectively catalytically hydrodechlorinating a polychlorophenol in liquid phase in an acid solvent medium which is at least partially aqueous, in the presence of a Group VIII noble metal catalyst and at least one Group 1b to 5a heavy metal, said polychlorophenol bearing chlorine substituents in both the meta- and ortho- and/or para-positions.

Abstract: The present invention relates to a process for the preparation of pyridine and substituted pyridines, in the vapor phase. These compounds are obtained by heating, at a temperature of 200.degree. to 500.degree. C., in the vapor phase:piperidine or piperidine substituted by one or more lower alkyl radicals;1,5-diaminopentane;1,5-diaminopentane containing, in its hydrocarbon part, from 1 to 3 linear or branched alkyl radicals having from 1 to 4 carbon atoms; orcompounds such as: N,N'-bis-(piperidin-2-yl)hydrazines,in the presence of a catalyst consisting of palladium, platinum or ruthenium deposited on a macroporous solid.The products obtained by the process according to the invention have various uses. Pyridine is used in particular as a solvent. .beta.-Picoline (or 3-methylpyridine) is used for the preparation of nicotinic acid or nicotinamide, used in pharmacy and in nutrition.

Abstract: A process for the dechlorination of aromatic nitro or amino compounds consists in reacting anilines or nitrobenzenes which are polysubstituted by chlorine, with hydrogen, under the action of heat, in the presence of iodide or bromide ions, in the liquid phase and at low pressure.The process makes it possible selectively to obtain anilines which are chlorine-substituted in the meta-position.

Abstract: A process for the dechlorination of aromatic nitro or amino compounds consists in reacting anilines or nitrobenzenes which are polysubstituted by chlorine, with hydrogen, under the action of heat, in the presence of cations (Bi, Pb, Sn, Tl, Hg and Ag), in the liquid phase and at low pressure.The process makes it possible selectively to obtain anilines which are chlorine-substituted in the meta-position.

Abstract: A process for the dechlorination of aromatic nitro or amino compounds comprising reacting anilines or nitrobenzenes, which are polysubstituted by chlorine, with hydrogen, under the action of heat, in the presence of an excess of chloride ions, in the liquid phase and at low pressure.The process makes it possible selectively to obtain anilines which are chlorine-substituted in the meta-position.

Abstract: A process for reducing .alpha.,.beta.-ethylenic aldehydes to the corresponding .alpha.,.beta.-ethylenic primary alcohols by hydrogen in the presence of a platinum-containing catalyst which has been pre-reduced in hydrogen at a temperature of at least about 50.degree. C. The process is highly selective in reducing the carbonyl group of the aldehyde in preference to the ethylenic unsaturation and said pre-reduced catalyst can be re-used in a series of aldehyde reductions without substantial loss in activity.