35 results about "P-bromophenol" patented technology

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 invention belongs to the field of organic synthesis of medicines, and particularly relates to a preparation method of an intermediate of a medicine metoprolol for treating hypertension. The synthetic route provided by the invention is as follows: p-bromophenol reacts with methyl vinyl ether in the presence of a palladium catalyst and a phosphine ligand to generate 4-(2-methoxyvinyl)phenol; andhydrogenating the 4-(2-methoxy vinyl)phenol in the presence of a palladium-carbon catalyst to obtain the target product 4-(2-methoxyethyl)phenol. The reaction steps of the method are short, the raw materials are cheap and are easily available, the process is simple, operation is convenient, no special reaction conditions are needed, and therefore, the method is more suitable for industrial production.

A method for preparing hydroxyaromatic compounds brominated in the para-position, such as p-bromophenol, is disclosed. The method yields overall high process selectivity through isomeric equilibration and separation of the brominated products, thereby eliminating the need for high para selectivity in the products of catalytic oxybromination reactions of hydroxyaromatic compounds using oxygen, a bromine source, and an acidic medium in the presence of a metal catalyst. Furthermore, the invention provides an efficient method for recycling the metal catalyst, as well as reagents used in the bromination, to further reactions.

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 discloses a synthesis method of 2,5-dibromoiodobenzene, comprising the following steps: S1, synthesis of 2-nitro-4-bromophenol; S2, synthesis of 2-amino-4-bromophenol; The synthesis of S3, 2-iodine-4-bromophenol; the synthesis of S4, 2,5-dibromoiodobenzene: 2-iodine-4-bromophenol is placed in a chemical reaction kettle, and then dioxane solvent is added, And stir at room temperature, gradually add phosphorus tribromide in this process, reactant is subjected to vacuum fractionation, collects 130-140 ℃, 3.25-3.45kPa fraction promptly obtains 2,5-dibromoiodobenzene, the present invention Utilize p-bromophenol as raw material, carry out the preparation of 2-nitro-4-bromophenol by p-bromophenol, then further prepare 2-amino-4-bromophenol, and then turn into 2-iodo-4-bromophenol , finally synthesized 2,5-dibromoiodobenzene, realized the synthesis and preparation of 2,5-dibromoiodobenzene in another way, expanded the preparation raw materials of 2,5-dibromoiodobenzene, and simultaneously the raw material parabromo Phenol is low in cost and large in quantity, making it convenient for industrial production.

The invention discloses a method for preparing alpha-alkynyl substituted ether compounds. The method comprises the following steps: taking propiolic acid as a raw material, and synthesizing substituted phenylpropiolic acid under conditions of substituted iodobenzene, 1,8-diazabicyclo[5.4.0]undec-7-ene, (beta-4)-platinu and dimethyl sulfoxide; taking substituted phenylpropiolic acid and p-bromophenol as raw materials, and synthesizing p-bromophenyl substituted phenylpropiolic acid ester under the conditions of 4-dimethylaminopyridine and N,N'-Dicyclohexylcarbodiimide; and performing an alkynylation reaction on the p-bromophenyl substituted phenylpropiolic acid ester in participation of tert-butyl hydroperoxide, cesium carbonate and tetrahydrofuran, and finally synthesizing alpha-alkynyl substituted ether products. According to the method disclosed by the invention, simple and readily available acetylene esters serve as an alkynylation reagent, and the target products, namely alpha-alkynyl substituted ether compounds, are synthesized in a green and environmental-friendly manner under mild conditions. The compounds play an important role in construction of multiple medical intermediates and bio-active structures.

The present invention provides a method for synthesizing magnolol. The magnolol is prepared from relatively cheap p-bromophenol, chloromethyl methyl ether and allyl bromide by being subjected to hydroxy protection and Grignard reaction to obtain allylphenol intermediate product; dissolving allylphenol into solvent; and carrying out oxidation coupling reaction in the presence of oxidation catalyst and introducing air or oxygen. The method is characterized in that the adopted catalyst is hydroxy*tetramethyl ethylene diamine copper (I) dichloride and has a molecular formula of [Cu(OH) / TMEDA]2Cl2, which allows p-allylphenol to carry out oxidation coupling reaction effectively and solves the problem of difficulty in industrial production of magnolol chemical synthesis; and the total yield of the synthesized magnolol product can reach 50%. The method has the advantages of simple synthetic process, high yield and low cost, and can be applied in industrial production. Comparing test results of infrared detection and high performance liquid phase analysis and detection with those of the magnolol product extracted from plants, the synthesized magnolol product has the similar or the same structure.

The present invention provides a novel sulfonyl chloride derivative, its preparation method and application. The structural formula of the sulfonyl chloride derivative is shown in Formula I. The preparation method comprises the following steps: 1) taking compound 1, i.e. p-bromophenol as a raw material, under the catalysis of a base, in a suitable organic solvent, substituting the phenolic hydroxyl group with ethyl chloroacetate to obtain compound 2, That is, 2-(4-bromophenoxy)ethyl acetate; 2) In a suitable organic solvent, the compound 2 is chlorosulfonated on the benzene ring with chlorosulfonic acid and a chlorinating reagent to obtain the compound of formula I. This derivative and its synthesis process have not seen any domestic and foreign literature reports at present, and there is no similar product on the market. The present invention designs a brand-new synthetic route, and optimizes the conditions for the key reaction steps in the route, and determines the optimal process conditions. The new process has the characteristics of cheap and easy-to-obtain starting materials, simple steps, easy post-processing and high yield, and is suitable for industrial production.

The invention provides a preparation method of an Eltrombopag intermediate and a preparation method of Eltrombopag diethanolamine salt, which relate to the technical field of medicinal chemistry. The preparation method of the Eltrombopag intermediate uses p-bromophenol as a raw material, and the nitration reaction does not have the problem of poor selectivity. After iodination, the yield of the coupling reaction between the compound of the intermediate formula (I) and phenylboronic acid is relatively high. Subsequent reduction reaction is carried out, the debromination reaction is complete, the yield is over 90%, and the purification is relatively simple. The synthesis yield of the compound of formula (I) is high and the operation is simple. Through the above improvements, the yield of the key compound of formula (I) is high, the follow-up treatment operation is simple, and the process is easy to scale up production. The yield of the whole synthesis process of Eltrombopag diethanolamine salt is 48.1%. The operation is simple, the three wastes are less, and it is suitable for scale-up Production.