5 results about "Chlorobenzene" patented technology

The invention discloses a preparation method of 2-amino-5-chloropyridine, and belongs to the field of organic chemical synthesis. The method comprises the following steps of using 2-amino-pyridine as a raw material and N-fluoro-N-chlorobenzene sulfonamide as a chlorinating agent, in an organic solvent, using imidazole ionic liquid as a catalyst, and carrying out a reaction, wherein a reaction temperature is 0 to 40 DEG C, and a reaction time is 0.2h to 24h. The method provided by the invention is simple and convenient in preparation process, mild in reaction condition, low in cost and high in product yield.

The invention provides a chlorphenamine maleate oxidation impurity, which has the structure defined in the specification. The invention also provides a preparation process of the chlorphenamine maleate oxidation impurity. According to the invention, the experiment results prove that the chlorphenamine maleate oxidation impurity generally exists in a chlorphenamine maleate finished product, and thestructure of the chlorphenamine maleate oxidation impurity is close to the structure of chlorphenamine maleate, so that the separation difficulty is relatively high; and the chlorphenamine maleate oxidation impurity is prepared by a simple process, can be used as a reference substance for quality control of chlorphenamine maleate, and has good application prospect.

The invention provides a preparation method of an energy-saving and environment-friendly flame retardant tetrabromobisphenol A. The preparation method comprises the following steps of: (1) adding a certain amount of bisphenol A into chlorobenzene, stirring for 0.5 h until the materials are uniformly mixed, and dropwise adding bromine and hydrogen peroxide at the same time at a specific temperature to obtain a tetrabromobisphenol A solution; and (2) heating the reaction system, carrying out curing reaction, standing after curing, separating out a water phase, collecting an organic phase, carrying out standing layering treatment for four times, cooling the organic phase collected after four-time standing layering to 8 DEG C by adopting frozen brine, and carrying out suction filtration to obtain a tetrabromobisphenol A product. According to the preparation method disclosed by the invention, the mother liquor can be used for more than 100 times, the generation of waste residues is reduced, and the use amount of sodium nitrite can be saved by 50%; after the mother liquor is recycled for 100 times, the chromaticity of the product is 20, the purity is 99.35%, and the yield is 99.8%; and the comprehensive yield of the product is 99.6%, and the average purity of the product is 99.54%.

The invention relates to a preparation method of 4-(9H-carbazol-9-yl)phenylboronic acid, belonging to the technical field of organic synthesis. The preparation method comprises the following steps: with carbazole as an initial raw material, subjecting carbazole to reacting with 4-chlorobromobenzene to generate 9-(4-chlorphenyl)-9H-carbazole; and then condensing 9-(4-chlorphenyl)-9H-carbazole with triethyl borate, and carrying out hydrolyzing to generate the 4-(9H-carbazol-9-yl)phenylboronic acid. According to the method, n-butyllithium is not used in the process of preparing the 4-(9H-carbazol-9-yl)phenylboronic acid, so an ultralow-temperature reaction is avoided, and all the reactions are carried out under mild conditions; and compared with an existing synthesis process, the method is more suitable for industrial production.