Abstract: The invention provides a process for preparing 1,3-diketones by rearrangement of the isomeric enol ester in a tube reactor comprising a heated portion and an unheated insulated portion which can optionally be provided with cooling means. The unheated portion of the reactor has a higher volume to surface ratio than the heated portion of the reactor. The reaction can be carried out adiabatically in the unheated portion of the reactor. The process and apparatus provide higher yields and selectivity to the 1,3-diketones.

Abstract: The invention relates to aqueous dispersions containing aminooxy crosslinking agents, of copolymers containing carbonyl groups, to processes for the preparation thereof and to the use thereof as a crosslinking system in binders, adhesives and coating agents.

Abstract: The invention relates to a process for the preparation of pyridine-2,3-dicarboxylic acid esters using novel maleic acid esters as starting materials. In the process, in a first process step, 2,3-dihalomaleic acid esters are reacted with ammonia, or ammonium salts, with the exclusion of water at a temperature of at least 50.degree.0 C. to form novel 2-amino-3-halomaleic acid esters, and these are subsequently reacted further in a second process step with .alpha.,.beta.-unsaturated aldehydes, or ketones, in the presence of an acidic catalyst and acid-binding agents at a temperature of at least 50.degree. C. with heat being supplied until the pyridine-2,3-dicarboxylic acid esters have been formed. Pyridine-2,3-dicarboxylic acid esters of this type can be used for example, as intermediates for synthesis of herbicides based on imidazoline. The present invention also relates to novel 2-amino-3-halomaleic acid esters, which are useful for producing the final product pyyridine-2,3-dicarboxylic acid esters.

Abstract: The invention relates to a process for the preparation of pyridine-2,3-dicarboxylic acid esters using novel maleic acid esters as starting materials. In the process, in a first process step, 2,3-dihalomaleic acid esters are reacted with ammonia, or ammonium salts, with the exclusion of water at a temperature of at least 50.degree. C. to form novel 2-amino-3-halomaleic acid esters, and these are subsequently reacted further in a second process step with .alpha.,.beta.-unsaturated aldehydes, or ketones, in the presence of an acidic catalyst and acid-binding agents at a temperature of at least 50.degree. C. with heat being supplied until the pyridine-2,3-dicarboxylic acid esters have been formed. Pyridine-2,3-dicarboxylic acid esters of this type can be used, for example, as intermediates for synthesis of herbicides based on imidazoline. The present invention also relates to novel 2-amino-3-halomaleic acid esters, which are useful for producing the final product pyridine-2,3-dicarboxylic acid esters.

Abstract: An improved process for the manufacture of 2-isopropyl-4-methyl-6-hydroxypyrimidine, starting from 3-aminocrotonic acid amide and an acylating agent, without isolating the intermediately formed 3-isobutyrylaminocrotonic acid amide. In a first process step, the acylation is carried out with excess isobutyric acid anhydride in the presence of an alkali metal salt of isobutyric acid at temperatures of from 50.degree. to 120.degree. C. and in the absence of a solvent. In a second process step, the cyclization is carried out in the resulting reaction mixture by the addition of an aqueous alkali metal hydroxide solution at temperatures of from 80.degree. to 105.degree. C., and then the hydroxypyrimidine is isolated in known manner. The total quantities of alkali metal hydroxide added in the second process step are such that they are sufficient both for the neutralization of the isobutyric acid present in the reaction mixture and also for the cyclization.

Abstract: The invention relates to an improved process for the manufacture of chloroacetaldehyde dimethyl acetal in which low-boiling constituents are distilled off completely or partially from the reaction mixture obtained by the reaction of vinyl acetate and chlorine in stoichiometric amounts in the presence of excess methanol, when the addition of chlorine is complete. The remaining liquid residue is neutralized with solid substances, such as oxides or carbonates of calcium and magnesium, while maintaining a temperature of from 20.degree. to 60.degree. C., until the aqueous extract has a pH of greater than 5. When neutralization is complete, the reaction mixture is in the form of two separate liquid phases. Once the upper organic layer has been separated off, it is fractionally distilled, pure chloroacetaldehyde dimethyl acetal being obtained as the main fraction yields of more than 90%, calculated on the vinyl acetate used.

Abstract: Process for the anilidization of carboxylic acid esters of the general formula R.sub.1 COOR.sub.2, wherein R.sub.1 is a cycloaliphatic or substituted cycloaliphatic radical with 3-8 C-atoms, preferably 5-6 C-atoms, an aromatic or substituted aromatic radical, preferably a heterocyclic or substituted heterocyclic radical, more particularly an oxygen-containing heterocyclic radical, with 4-5 C-atoms, and R.sub.2 is a hydrocarbon radical with up to 4 C-atoms, preferably 1-2 C-atoms, wherein such esters are reacted in the presence of aniline with equimolar amounts of magnesium dianilide and/or aluminum trianilide in the fluid phase. The products obtained are used as intermediates or directly as pesticides.

Abstract: A process for the manufacture of furancarboxylic acid anilides of the general formula ##STR1## in which R.sub.1 represents an aryl group or an alkyl group, R.sub.2 and R.sub.3 each represent an alkyl group or hydrogen, by a ring-closure reaction of a .beta.-ketoester with an .alpha.-haloaldehyde or .alpha.-haloketone, in the presence of a stoichiometric amount of a halide-binding substance to form a furancarboxylic acid ester, and by subsequent anilidation, the reaction being performed in two stages, the ring-closure reaction being carried out in the presence of a mixture of alkaline earth metal carbonates and pyridine in a ratio of from 1000 to 5:1 Val, based on the hydrohalic acid liberated, at temperatures between 50.degree. and 100.degree. C.

Abstract: An improved process for preparing methylchlorosilanes which comprises reacting tetramethylsilane and hydrogen chloride in the gaseous state with a solid Friedel-Crafts catalyst.

Abstract: A process for preparing methyltin chlorides which comprises reacting tetramethylsilane with tin tetrachloride.

Abstract: 2,4,4-Trichlorobutadienyl-1-phosphate and 1-phosphonates are novel compounds, and are effective against organisms such as insects, acarides, and nematodes, and are suitable for application to plants.