GM Phenacetin

The antipyretic effect of phenacetin is stronger than its analgesic effect. The efficacy is comparable to aspirin, with a slow and long-lasting effect and low toxicity. Research has shown that both this product and its metabolite paracetamol have antipyretic effects. When enzyme inhibitors are used to prevent the conversion of phenacetin to paracetamol, significant antipyretic effects can still be observed. The antipyretic effect that occurs after administering the product is not only caused by its active product, paracetamol.

side effect

Long term use of preparations containing phenacetin may cause necrosis of renal papilla, interstitial nephritis, and even renal pelvis cancer and bladder cancer. Fenacetin also easily causes hemoglobin to form methemoglobin, reducing blood oxygen carrying capacity and causing cyanotic reactions. In addition, phenacetin can also cause hemolysis and hemolytic anemia, and has certain toxicity to the retina. Long term use of phenacetin can also lead to drug dependence. Foreign countries such as the United States, Britain, Germany, Japan, etc. have decided to cancel phenacetin or stipulate that its packaging must indicate "cannot be taken for a long time or in large doses".

chemical property

A white, glossy, scaly crystalline or white crystalline powder. Melting point 137-138 ℃, refractive index 1.571. Insoluble in water, slightly soluble in ether, slightly soluble in boiling water, soluble in ethanol and chloroform. When dissolved in concentrated sulfuric acid, it does not show color. When nitric acid is added to the solution, it turns orange yellow. Odorless, slightly bitter in taste.

Purpose

Acetaminophenethyl ether is used as an organic synthesis raw material and a pharmaceutical intermediate.

Purpose

Raw materials for scientific research

Purpose

Substrates for CYP1A2 and CYP2D6.

Purpose

Antipyretic and analgesic drugs, used to treat fever, headache, neuralgia, etc. The ingredients include APC tablets and analgesic agents, as well as aspirin and caffeine. Fenacetin is reasonably believed to be a human carcinogen; Analgesics containing phenacetin are listed as known human carcinogens.

Production methods

(1) Obtained by acetylation of p-aminophenyl ether. Heat a mixture of benzene, acetic anhydride, and p-aminophenethyl ether on an oil bath and azeotrope for 4 hours. After the reaction is complete, cool the reactants to precipitate phenatine, filter, wash with cold benzene, and dry to obtain a yield of 86% of the theoretical amount. (2) Obtained by the interaction of acetaminophenol and sodium ethanol: first, acetaminophenol is added to sodium ethanol, then slowly added to iodoethane, heated and refluxed for 1 hour, cooled, and filtered. The crude product obtained is dissolved in ethanol, filtered, and the filtrate is diluted with hot water, then cooled, filtered, and dried to obtain a finished product with a yield of 80% of the theoretical amount. The first method can also use acetic acid instead of benzene as a solvent, and the process is as follows. Heat 40% dilute acetic acid to boiling point, add p-aminophenethyl ether, evaporate to remove water, add glacial acetic acid when the temperature rises to 150 ℃, reflux for 1 hour, continue to steam, and wait for the temperature to rise above 150 ℃. Take a sample to measure free aminophenethyl ether, add acetic anhydride according to the remaining amount of aminophenethyl ether, reflux for 0.5 hours, check the endpoint, and reduce pressure after passing the test. Recycle acetic acid until the amino content is below 0.046 and the acid content is below 0.2%. Inject the reaction hydraulic pressure into the hot refined mother liquor, stir and cool to 40 ℃, filter, and obtain the crude product of phenacetin. Refine, add boiling water or refined mother liquor to crude phenacetin, heat, stir and dissolve, filter, adjust the filtrate to pH=4.5-4.7 with acid, add activated carbon and sodium thiosulfate, stir and decolorize, filter, cool and crystallize the filtrate, shake and filter, and air dry to obtain phenacetin.