Application background and overview of 4-mercaptopyridine
4-Mercaptopyridine can be used as an intermediate in pharmaceutical synthesis and chemical materials. If 4-mercaptopyridine is inhaled, move the patient to fresh air; if the skin comes in contact, take off contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical treatment if you feel uncomfortable; if the eyes come into 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.
Application structure of 4-mercaptopyridine
Applications of 4-mercaptopyridine
4-Mercaptopyridine can be used as an intermediate in pharmaceutical synthesis and chemical materials. Examples of its application are as follows:
1) Prepare benzathine cefapirin. The method uses bromoacetyl 7-ACA as a raw material and includes: reacting bromoacetyl 7-ACA with 4-mercaptopyridine in a solvent in the presence of an organic base to obtain solid cefpirin acid; then, into the reaction solution, Add an inorganic base to dissolve cefpirin acid into a salt, and optionally add a reducing agent. The reducing agent is sodium thiosulfate, sodium bisulfite or vitamin C; then add A to the reaction solution. Reagent, cefpirin salt reacts with reagent A at 0 to 50°C for 0.1 to 20 hours to obtain benzathine cefpirin, in which reagent A is dibenzylethylenediamine acetate or dibenzylethylenediamine. This method solves the problems that the product is easy to decompose and the color is easy to deepen when preparing cefpirin sodium salt. The steps are simplified, easier to operate, suitable for industrial production, and the product quality meets the quality standard of USP29.
2) Preparing 1-benzyl-4-thiobenzyl-pyridinium salt iodide, including the following steps: Mix iodine element, 4-mercaptopyridine, benzyl alcohol and a small amount of water in acetonitrile, and heat it under solvothermal conditions , react at 100℃~150℃ for 1000~7000 minutes to prepare 1-benzyl-4-thiobenzyl-pyridinium salt iodide, and then use gradient cooling method to precipitate 1-benzyl-4-thiobenzyl-pyridinium salt iodide . Since the present invention uses benzyl alcohol instead of benzyl halide as the benzylation reagent, the toxicity during the synthesis process is reduced; and the method has a higher yield, between 70% and 80%, and the final product is crystalline and has high purity. ; In addition, the method of the present invention has simple equipment, simple method, cheap and easily available raw materials, low cost, and no inert gas protection is required during the reaction process.
3) Preparation of the salt trifluoromethylpicolinic acid Loratrix. The step is to perform Beckmann rearrangement of 3-bromo-4-methyl-α-oximeacetanilide in concentrated sulfuric acid at 50°C-100°C for 0.5-2.0 hours to obtain 4-bromo5-methylisatin. 4-Bromo-5-methylisatin is oxidized with H2O2 in a strong alkaline solution at 40℃-100℃ for 1.0-4.0 hours to prepare 5-methyl-6-bromoanthranilic acid, 5-methyl-6-bromo Anthranilic acid is heated and dissolved in 3.5-10.0% dilute sulfuric acid and then forms a ring with dicyandiamide. After neutralization, 2-guanidino-3,4-dihydro-5-bromo-6-methylquinazoline is obtained. -4-one, 2-guanidino-3,4-dihydro-5-bromo-6-methylquinazolin-4-one is dissolved in ethylene glycol, then a strong base, 4-mercaptopyridine and copper salt are added The catalyst is heated to reflux for 1-10 hours, and after cooling, hydrochloric acid is added to neutralize to obtain loratrich hydrochloride. This synthesis process has short reaction steps, high overall yield, low cost, cheap price, easy operation and convenient production.
4) Prepare a sulfide-containing metal complex, which is characterized by: mixing iodine element, metal iodide, alcohol and 4-mercaptopyridine in acetonitrile, reacting under solvothermal conditions, so that the alkyl group on the alcohol Transfer to the sulfur atom of the mercapto-containing compound to generate a sulfide compound; since sulfide-containing ether metal complexes containing different metal lutidines can be synthesized by changing the alcohol and changing the metal iodide, the sulfur-containing ether metal complex of the present invention The synthesis method of ether metal complexes has strong applicability; at the same time, because alcohol is used as the raw material to provide the corresponding alkyl group, the toxicity is relatively small. Moreover, alcohols have more types than halogenated hydrocarbons or alkenes, so more alcohols can be produced. Various types of thioether compounds.
