摘要:
Process for converting a nitrobenzene into a free aminophenol by catalytic reduction hydroxylation in the presence of an aqueous-acidic reaction medium.
摘要:
p-Haloalkoxyanilines are obtained from the corresponding nitrobenzenes by catalytic hydroxylation in the presence of an aqueous acidic reaction medium with the formation of a corresponding aminophenol and reaction of this aminophenol with a halogenated olefin in the presence of water and a catalytic amount of base.
摘要:
The invention relates to a method for the preparation of 4,6-dichloropyrimidine by reacting 4-chloro-6-methoxypyrimidine with at least one sulphur-containing chlorinating agent selected from the group consisting of SCl2, SOCl2, and SO2Cl2 in the presence of at least one phosphorus compound having the formula R3P═Yn (1), in which R represents C1-C10-alkyl or C6-C10-aryl, each of which may optionally be substituted by up to five identical or different substituents selected from the group consisting of fluorine, chlorine, bromine, C1-C4-alkyl, and C1-C4-alkoxy, Y represents oxygen or sulphur, and n represents zero or 1.
摘要:
2-Chloroacrylonitrile is prepared in a particularly advantageous and readily industrially practicable manner by chlorinating acrylonitrile and then thermally cleaving the 2,3-diehloropropionitrile formed, by chlorinating acrylonitrile in the presence of a catalyst system comprising dimethylformamide and pyridine and/or pyridine derivatives and subjecting the resulting crude 2,3-dichloropropionitrile to thermal cleavage in the presence of the same catalyst system without the addition of further catalysts.
摘要:
The invention relates to a method for the preparation of 4,6-dichloropyrimidine by reacting 4-chloro-6-methoxypyrimidine with phosgene as chlorinating agent in the presence of a nitrogen-containing auxiliary.
摘要:
The present invention relates to a process for preparing 4,6-dichloro-pyrimidine by reaction of 4-chloro-6-methoxypyrimidine with an acid chloride in the presence of a hydrogen halide.
摘要:
Acetophenones which are substituted on the aromatic ring by fluoroalkyl are prepared in a particularly advantageous, environmentally friendly and effective manner from fluoroalkylanilines and acetaldoxime by preparing from a fluoroalkylaniline a corresponding diazonium salt solution, and reacting this with acetaldoxime in the presence of at least one copper compound, without adding any buffer salts or reducing agents, carrying out the reaction at from 20 to 50° C. and in the presence of halide ions and subsequently heating to a temperature in the range from 70 to 110° C.
摘要:
The invention relates to a process for the preparation of 4,5,6-trichloro- and 2,4,5,6-tetrachloropyrimidine starting from 3-dimethylamino-propionitrile, to its use and also to a crystalline intermediate product form.