Application background and overview of pyridinium tribromide
Pyridinium tribromide is also known as pyridinium tribromide and pyridinium tribromide in Chinese. Pyridinium tribromide can be used as an intermediate for pharmaceutical and chemical synthesis. If pyridinium tribromide is inhaled, move the patient to fresh air; if there is skin contact, take off contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical treatment if you feel uncomfortable; if there is eye contact, separate Rinse the eyelids with running water or saline and seek medical attention immediately. If ingested, rinse mouth immediately. Do not induce vomiting and seek medical attention immediately.
Applications of pyridine tribromide[1-5]
Pyridine tribromide can be used as an intermediate for pharmaceutical and chemical synthesis. Examples of its application are as follows:
1. Synthesis of sulfoxide compounds. Sulfoxide compounds are chemically and biologically active organic intermediates that are widely found in biologically active drugs, such as anti-ulcer drugs, antibacterial drugs, antifungal drugs, anti-arteriosclerosis drugs, antihypertensive drugs, Cardiotonic agents, anti-vasodilators, etc. Due to the wide application of sulfoxide compounds in the biological and medical fields, people are increasingly investing in the study of thioether oxidation reactions. Use ethanol as the solvent, pyridine tribromide and nitrate as the catalyst, and oxidize the thioether in the air to synthesize crude sulfoxide compounds at room temperature; or use ethanol as the solvent, liquid bromine and nitrate as the catalyst, and use room temperature conditions Under this condition, thioether is oxidized in air to synthesize crude sulfoxide compound; the method is simple to operate, does not produce products that pollute the environment, is very environmentally friendly, overcomes the shortcomings of some thioether selective oxidation reactions, and has no transition Metal catalyst, mild reaction conditions, less catalyst dosage, high oxidation selectivity and high yield.
2. Prepare 2-bromothiophene and its derivatives whose structure is shown in formula (II). Mix thiophene or its derivatives with the structure shown in formula (I) and an organic solvent and control the temperature at -50~20°C. Add a brominating agent and complete the insulation reaction. After sufficient reaction, separate the aqueous layer and concentrate the organic layer. Distillation obtains 2-bromothiophene or its derivative products; the brominating agent is selected from one of the following: ① pyridinium tribromide, ② a mixture of pyridine compounds and bromine, ③ pyridine compounds, bromine and A mixture of hydrogen peroxide, ④ a mixture of pyridine methyl tetrahydrofuran compounds, bromine, hydrogen peroxide and hydrobromic acid, ⑤ a mixture of pyridine compounds, hydrobromic acid and hydrogen peroxide, ⑥ pyridine compounds, bromine and hydrobromic acid; the The organic solvent is methylene chloride or chloroform or dichloroethane. The invention has the advantages of cheap and easy-to-obtain raw materials, low toxicity, high chemical reaction selectivity, high yield, good product quality, and recyclable brominating agent.
3. Preparation of diaminetetraacetic acid chelated difluoropyridine resin. The method includes the following steps: preparation of brominated polystyrene, washing 1,2-divinylbenzene three times with 10% mass fraction of sodium hydroxide solution and deionized water, taking the upper layer of light yellow liquid and placing it in the refrigerator for cooling for later use; Pour an appropriate amount of methylene chloride into the flask, cool it in an ice-water bath, and keep the temperature below 5°C; add the washed 1,2-divinylbenzene into the flask, and then slowly add pyridinium tribromide into the flask in batches for 30 Complete the addition within -min, stir continuously in an ice water bath until the mixed solution turns into a transparent reddish brown, then filter and vacuum distill until there are no more bubbles in the reddish brown liquid. The distilled fraction is methylene chloride, which is recovered for later use. Use it next time; the oily blood-red liquid remaining in the flask is divinylbenzene bromide; the process of the invention is simple, easy to operate, and can improve product quality and comprehensive performance.
4. Prepare a macamide compound. It includes: linoleic acid and an oxidizing agent are catalytically oxidized by a pyridine derivative to obtain a macaene mixture; the macaene mixture is amidated with benzylamine or a benzylamine derivative and then separated by preparative chromatography; wherein: the oxidizing agent is 2, 2, Any one of 6,6-tetramethylpiperidine-nitrogen-oxide, tribromopyridinium, and 2-iodoacylbenzoic acid; the benzylamine derivative is 3-methoxybenzylamine or 3,4-di Methoxybenzylamine. The present invention uses linoleic acid as the starting reactant for synthesis. Compared with the prior art of extracting macamide from plant maca, the required raw materials are cheap and easy to obtain; in addition, during the synthesis and preparation process, The operation is simple, there are few by-products, and the required reagents and solvents are low in toxicity and easy to obtain. Provide a new route for the large-scale preparation of macamide monomer compounds.
5. Prepare a pyrrolopyridine compound. This compound is methyl 1-((2-(trimethylsilyl)ethoxy)methyl)-1H-pyrrolo[2,3-b]pyridin-2(3H)-one-4-carboxylate Ester, the preparation method is as follows: (1) Compound SM is protected with 2-(trimethylsilyl)ethoxy)methyl (sem) to obtain compound 1; (2) Compound 1 is dehydrogenated by pyridinium tribromide/ Oxidation gives compound 2; (3) Debromination of compound 2 by zinc and ammonium chloride at room temperature gives compound 3; (4) Using an autoclave, compound 3 undergoes a carbonyl insertion reaction under the catalysis of Pd(dppf)Cl2 to generate the final product compound 4; The final product has broad application prospects in cancer treatment.
