摘要:
A first alkanol having 1 to 3 C atoms or a mixture of this first alkanol with water or water itself can be separated off from oxygen-containing organic compounds having 3 to 7 C atoms from the group comprising second alkanols and dialkyl carbonates, which always have at least 2 C atoms more than the first alkanol, by permeation on membranes if a membrane obtained by plasma polymerization is employed.
摘要:
A process is described for the preparation of dialkyl carbonates by oxidative carbonylation of the corresponding alcohol in the presence of a copper-containing catalyst at elevated temperature and elevated pressure, which process permits simple separation of the copper-containing catalyst by sedimentation, and of the reaction water in the case of methanol by simple distillation from the reaction solution.
摘要:
New polysaccharide carbonates are produced by acylation of polysaccharides with carbonic acid esters and have degrees of substitution of preferably 0.5 to 3.
摘要:
The present invention relates to new 5-trihalogenomethyl-isoxazoles of the formula (I) ##STR1## in which x represents 1, 2 or 3, and a process for their preparation by reacting the corresponding trichloromethylisoxazole with a fluorinating agent.
摘要:
Arthropodically active 3-halogenoalkyl-1-arylpyrzoles of the formula ##STR1## in which R.sup.1 represents halogenoalkyl,R.sup.2 represents cyano, or represents hydroxycarbonyl, or represents carbamoyl or thiocarbamoyl, or represents alkoxycarbonyl, N-alkylcarbamoyl or N,N-dialkylcarbamoyl, or represents alkenyloxycarbonyl, N-alkenylcarbamoyl or N,N-dialkenylcarbamoyl, or represents alkinyloxycarbonyl, N-alkinylcarbamoyl, N,N-dialkinylcarbamoyl or N-arylcarbamoyl, or represents alkylcarbonyl, halogenoalkycarbonyl or cycloalkylcarbonyl,R.sup.3 represents hydrogen, alkyl, halogenoalkyl or cycloalkyl andAr represents substituted phenyl, with the exception of the 2,4-dinitrophenyl radical.
摘要:
The invention relates to a method for the thermal decarboxylation of dicarboxylic acids, in particular to 3,4-ethylene dioxythiophene-2,5-dicarboxylic acid as an educt. According to said method the educt is used in solid form and/or the reaction is carried out in the presence of a plurality of fluidised bed bodies. No solvents are used in the reaction and the decarboxylation product that is formed during the reaction is carried away from the reaction zone in gaseous form.
摘要:
The invention relates to substituted or unsubstituted benzodioxinothiophenes, their preparation and their use for preparing electrically conductive oligomers or polymers, also oligomers or polymers comprising these thiophene derivatives as repeating unit.
摘要:
The invention relates to a process for preparing 4-chlorobiphenyl by (a) reacting biphenyl and chlorine in the presence of one or more ring-chlorination catalysts, and (b) subjecting the reaction mixture obtained in step (a) to fractional distillation to obtain 4-chlorobiphenyl.
摘要:
A process is provided for preparing 4-hydroxy-3-nitrobiphenyl from 4-hydroxy-biphenyl by nitrating in the position adjacent to the phenolic hydroxyl group in high selectivity and yield, and the nitric acid used as the nitrating reagent is metered into the reaction system in a specific manner.
摘要:
The present invention relates to a process for preparing trimethylol compounds and formic acid by reaction of formaldehyde and aldehydes in the presence of a nitrogen base and distillation of the resulting reaction mixture in the presence of an auxiliary.