Abstract: Cyclic ketones, notably cyclopentanone and 2,2-dimethylcyclopentanone, are simply, economically and efficiently prepared, even on an industrial scale, by decarboxylating/cyclizing a dicarboxylic acid, in liquid phase, in the presence of a catalytically effective amount of a metal or compound thereof selected from among boron, aluminum, gallium, indium, thallium, tin, antimony, bismuth, molybdenum, rubidium, cesium and vanadium.

Abstract: Mono- or polycarboxylic acid esters are prepared by reacting a salt of such carboxylic acid with an organic halocompound, e.g., a (cyclo)alkyl, (cyclo)alkenyl, aryl or aralkyl halide, in an aqueous reaction medium, in the presence of a catalytically effective amount of a phase transfer catalyst, for example an onium salt.

Abstract: The vanillic acid esters, for example, methyl or ethyl vanillate, are effective perfuming or olfactory agents for a wide variety of compositions, substrates and articles, whether perfumes, skin- and haircare products, cosmetics, shaving preparations, toiletries, deodorants and antiperspirants, room deodorizers, etc.

Abstract: Cyclic ketones, notably cyclopentanone and 2,2-dimethylcyclopentanone, are simply, economically and efficiently prepared, even on an industrial scale, by decarboxylating/cyclizing a dicarboxylic acid, in liquid phase, in the presence of a catalytically effective amount of a condensed or uncondensed neutral phosphate.

Abstract: A process for the preparation of 2,2-difluoro-1,3-benzodioxole from 2,2-dichlorol,3-benzodioxole. 2,2-Difluoro-1,3-benzodioxole is prepared by reaction of 2,2-dichloro-1,3-benzodioxole with potassium fluoride in the presence of an effective quantity of a catalyst selected from potassium hydrogen fluoride, sodium hydrogen fluoride, cesium hydrogen fluoride, rubidium hydrogen fluoride, and quaternary ammonium hydrogen fluoride. 2,2-Difluoro-1,3-benzoxodiole is an intermediate compound which is used particularly for the preparation of products for agricultural chemistry and for the synthesis of pharmaceutical products.

Abstract: A process for the preparation of aromatic aldehydes by formylation of aromatic compounds in liquid hydrofluoric acid in the presence of boron trifluoride.

Abstract: 3-Methoxy-4,5-methylenedioxybenzaldehyde is facilely and improvedly prepared by reacting 4,5-dihydroxy-3-methoxybenzaldehyde with a dihalomethane in a two-phase reaction medium and at a pH of from 7 to 12.

Abstract: 3,4,5-Trialkoxybenzaldehydes, notably 3,4,5-triamethoxybenzaldehyde, are prepared by hydrolyzing 5-bromo-4-hydroxy-3-methoxybenzaldehyde with an alkali metal hydroxide, in water and in the presence of a copper catalyst, and then directly sequentially (i.e., without separating any reaction intermediates) etherifying the 4,5-dihydroxy-3-methoxybenzaldehyde thus produced with a lower alkyl halide, in an aqueous medium and at a pH maintained at a value of from 6 to 12, optionally in the presence of a catalyst.

Abstract: Novel N-[(meth)allyloxy-mono-/di(meth)allylphenyl]maleimides, in admixture with at least one N-[(meth)allyloxyphenyl]maleimide, are reacted with at least one bismaleimide, and optionally a hydroxylated organosilicon compound, in the presence of an imidazole compound, to obtain mechanically improved thermosetting imido copolymerizates well adapted for the production of, e.g., coatings, adhesive bondings, laminates and composites.

Abstract: N,N'-bis(2-hydroxyethyl)oxamide is facilely prepared, e.g., in finely divided crystalline form, by reacting an alkyl oxalate with ethanolamine in an aqueous reaction medium.

Abstract: The invention relates to new diazotype materials of which the sensitive layer contains, as a base generator, a compound comprising a basic part and an acid part, the acid part being a 2-carboxycarboxamide group and the basic part consisting of an alkali metal cation or alkaline earth metal cation or a tetraalkylammonium cation.These diazotype materials develop rapidly and possess an excellent resistance to ageing.

Abstract: Symmetric ureas are converted to aliphatic isocyanates in high yields by reacting said ureas with phosgene at temperatures of at least 150.degree. C. and in a solvent having a boiling temperature greater than 150.degree. C.

Abstract: Vinyl chloride polymers are heat stabilized by formulating therewith minor amounts of [1] a divalent metal salt of an organic carboxylic acid and [2] either a .beta.-diketone or a .beta.-keto-aldehyde.