35 results about "P-bromophenol" patented technology

The invention discloses a method for synthesizing phenetyl, which uses p-chlorophehol or p-bromophenol as starting reaction raw material. It first uses methyl, benzyl or tert-butyl to protect the phenolic hydroxyl, the parivis which is protected by the phenolic hydroxyl reacts with the magnesium in the ether, tetrahydrofuran, tert-butyl methyl ether, isopropyl ether and its mixing solution to obtain the Grignard reagent, the Grignard reagent directly reacted with the etox to obtain the tyrosol which is protected by the phenolic hydroxyl, the tyrosol reacts with the dimethyl sulfate, dimethyl carbonate, trimethyl orthoformate to obtain the tyrosol ether which is protected by phenolic hydroxyl, which obtains the product in acid or hydrogenation protection.

The invention relates to a preparation method of 4-hydroxyphenethyl alcohol. The preparation method is characterized in that: p-bromophenol is taken as a raw material, and is subjected to a series of reactions such as hydroxyl protection, Grignard reaction, and protecting group removing so as to obtain 4-hydroxyphenethyl alcohol. Product yield of the preparation method reaches about 90%.

The invention belongs to the field of organic synthesis of medicines, and particularly relates to a preparation method of an intermittent of a medicine metoprolol for treating hypertension. A synthesis route of the method comprises the steps that in the presence of a palladium catalyst and a phosphine ligand, p-bromophenol is reacted with methyl vinyl ether to generate 4-(2-methoxy vinyl)phenol; the 4-(2-methoxy vinyl)phenol is subjected to hydrogenation in the presence of a palladium carbon catalyst to obtain the target product 4-(2-methoxyethyl)phenol. The reaction steps are short, the raw materials are cheap and easy to obtain, a technology is simple, operation is convenient, and no special reaction conditions are needed, so that the method is more suitable for industrial production.

The invention provides a preparation method of an eltrombopag intermediate and a preparation method of eltrombopag diethanolamine salt, and relates to the technical field of medicinal chemistry. According to the preparation method of the eltrombopag intermediate, p-bromophenol is taken as a raw material, and the problem of poor selectivity of nitration reaction is solved. After iodination, the coupling reaction yield of the intermediate compound as shown in a formula (I) and phenylboronic acid is high. Subsequently reduction reaction is carried out, the debromination reaction is complete, the yield is 90% or more, the refining is simpler, and the synthesis yield of the compound of the formula (I) is higher and the operation is simple. Through the improvement, the yield of the key compound shown as the formula (I) is relatively high, the subsequent treatment operation is simple, the process is easy for amplified production, the yield of the whole synthesis process of the eltrombopag diethanolamine salt is 48.1%, the operation is simple, less three wastes are generated, and the synthesis process is suitable for amplified production.

The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 4-(4-hydroxyphenyl) cyclohexanone. According to the preparation method, p-bromophenol is used as a raw material, a Grignard reagent is prepared through hydroxyl protection and Grignard reaction, then the prepared Grignard reagent is utilized to couple with 1,4-cyclohexanedione monoethyleneglycol ketal, then the product is dehydrated to obtain alkene, and double protecting groups are removed after hydrogenation to prepare a target product, namely, 4-(4-hydroxyphenyl) cyclohexanone. Thepreparation method of 4-(4-hydroxyphenyl) cyclohexanone, provided by the invention, has the advantages of reasonable process design, high yield and low production cost; the prepared 4-(4-hydroxyphenyl) cyclohexanone is a white solid, the HPLC content is more than 99.5%, the total yield of the product can reach 75-80%, and the raw materials are easy to obtain; and the method has simple operation and high safety, and realizes industrial production of 4-(4-hydroxyphenyl) cyclohexanone.

The invention relates to a preparation method of 4-bromophenetole. The method comprises (1) an etherification reaction step: putting p-bromophenol and diethyl sulfate into a reaction kettle, stirring, heating and continuously adding potassium hydroxide to react; (2) a washing step: adding water to the mixture after the etherification reaction, evenly stirring, standing still to delaminate and separate oily liquid; and (3) a distillation step: introducing vapor in the oily layer for vapor distillation to obtain the finished product of 4-bromophenetole. By using a vapor distillation technology and potassium hydroxide, the preparation method reduces the feeding amounts of diethyl sulfate and water, saves the cost of the raw materials, improves the product quality and enhances the 4-bromophenetole content to 99.5 percent.

The invention belongs to the field of organic synthesis of medicines, and particularly relates to a preparation method of a medicine esmolol hydrochloride intermediate for treating hypertension. The synthesis route provided by the invention comprises the following steps: reacting p-bromophenol with methyl acrylate in the presence of a palladium catalyst and a phosphine ligand to generate 3-(4-hydroxyphenyl) methyl acrylate; and hydrogenating the generated 3-(4-hydroxyphenyl) methyl acrylate in the presence of a palladium-carbon catalyst to obtain a target product methyl 4-hydroxyphenylpropionate. The method has the advantages of short reaction steps, cheap and accessible raw materials, simple technique and convenience of operation, and does not need special reaction conditions, thereby being more suitable for industrial production.

The invention belongs to the technical field of medicine synthesis, and particularly relates to a pramoxine hydrochloride preparing method. The method includes reacting p-bromophenol and 1-bromobutaneunder catalytic functions of an alkali to prepare an intermediate that is 1-bromo-4-tert-butoxybenzene; synthesizing pramoxine having a base group from the 1-bromo-4-tert-butoxybenzene and 3-morpholinopropanol with the existence of a strong alkali; and subjecting the pramoxine having the base group to salification to obtain the pramoxine hydrochloride. The yield of the pramoxine hydrochloride prepared by the method is higher than 80%, and liquid-phase purity of the prepared pramoxine hydrochloride is higher than 99.8%. The method is used for preparing the pramoxine hydrochloride, and is simple to operate and high in yield, raw materials are easily available, product purity is high, the cost is low, and pollution is low.

The invention relates to a preparation method of p-bromoethoxybenzene, comprising the following steps: (1) etherification reaction: throwing p-bromophenol and diethyl sulfate into a reaction kettle, stirring, heating, distributing and adding sodium hydroxide to react; (2) washing: adding water to a mixture after etherification reaction, evenly stirring, standing and layering to separate out oily liquid; and (3) rectification: rectifying an oil layer by an efficient rectification tower to obtain the finished product. In the preparation method, the efficient rectification tower is used for rectification instead of the original distillation operation, thus reducing the usage amount of diethyl sulfate and water, keeping the reaction temperature at 30-50 DEG C, saving energy, obtaining high-quality and high-content p-bromoethoxybenzene, achieving high content of p-bromoethoxybenzene up to 99.5% and enhancing the market competitiveness of the product.

The invention relates to a method for preparing 4-hydroxy-4'-cyanobiphenyl, and belongs to the technical field of organic synthetic chemistry. According to the method, substituted boronic acid is first prepared by taking p-bromophenol as a raw material, and then the substituted boronic acid is prepared into the 4-hydroxy-4'-cyanobiphenyl, wherein PG in the substituted boronic acid is a protectinggroup, the substituted boronic acid and p-chlorobenzonitrile are subjected to a Suzuki coupling reaction in the presence of a solvent, an alkali and a catalyst, deprotection is performed to obtain the4-hydroxy-4'-cyanobiphenyl, the molar ratio of p-bromophenol, p-chlorobenzonitrile and the alkali is 1.0:(1.0-1.5):(2.0-4.0), and the temperature of the Suzuki coupling reaction is 50-120 DEG C. Themethod provided by the invention has the advantages that the production efficiency is high, three wastes are fewer, raw materials are easy to obtain, the cost is low, and the obtained product, namely,4-hydroxy-4'-cyanobiphenyl, is high in yield.

Brominated hydroxyaromatic compounds such as p-bromophenol are prepared by contacting a hydroxyaromatic compound with oxygen and a bromine source such as hydrogen bromide or an alkali metal or alkaline earth metal bromide in an acidic medium, in the presence of elemental copper or a copper compound as catalyst. The brominated product of this reaction may be converted alternately to a dihydroxyaromatic compound such as hydroquinone by hydrolyses, or a dihydroxybiphenyl compound such as 4,4′-dihydroxybiphenyl by reductive coupling.

The present invention provides a preparation method of p-bromophenol compound. The method is characterized in that high selectivity preparation of p-bromophenol is conducted on the raw material phenol compound by using a transition metal catalyst in an oxygen-containing atmosphere.

The invention relates to the technical field of medicine synthesis, in particular to an industrial preparation process of tamoxifen citrate. The preparation process comprises the following steps: (1) etherification: taking p-bromophenol and dimethylaminochloroethane hydrochloride as raw materials, taking methylbenzene as a solvent, and carrying out etherification reaction under the action of sodium hydroxide to obtain etherate; (2) Grignard reaction: by taking tetrahydrofuran as a solvent, reacting the etherate with an initiator to obtain a Grignard reagent, and then carrying out Grignard reaction on the Grignard reagent and alpha-ethyl desoxybenzoin to obtain a Grignard substance; (3) dehydration and alkalization: carrying out a dehydration reaction on the Grignard substance and hydrochloric acid, and then carrying out an alkalization reaction with a sodium hydroxide solution to obtain tamoxifen free alkali; and (4) salt forming reaction: taking the tamoxifen free alkali and citric acid as raw materials, taking acetone as a solvent, and carrying out salt forming reaction to obtain the tamoxifen citrate. The process conditions are easy to control, the product purity reaches 99.5%, the total yield of the product is high, and the production cost is low.