Acetphenetidin for Analgesic powder Pharmaceutical Raw Materials Phenaceti
Melting point 133-136 °C(lit.)
Boiling point 132 °C / 4mmHg
storage temp. 2-8°C
Water Solubility 0.076 g/100 mL
Stability: Stable. Incompatible with strong oxidizing agents, strong acids.
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1. Used for organic synthesis of raw materials and drug intermediates from acetaminophen ether.
2. Antipyretic analgesics for the treatment of fever, headache, neuralgia.
3. Active pharmaceutical ingredient for Scientific Research.
The antipyretic and analgesic effects of phenacetin are similar to that of acetylsalicylic acid, which is mainly used as anti-inflammatory drugs with a slow and long-lasting effect. It is an effective drug on the treatment of headache, neuralgia, joint pain and fever. However, it has a weak effect on treating anti-rheumatic, anti-inflammatory. Overdose can cause methemoglobinemia, resulting in hypoxia. Long-term medication can damage the kidneys, and even cause papillary necrosis, thus it should be taken with caution. Owing to its side effect and the rapid development of other similar drugs, the drug has been discontinued alone and just used as an active pharmaceutical ingredient for compound preparation with other drugs. It is often combined with aspirin, caffeine, for making aspirin compound (0.162 g of non-phenacetin, 0.227 g of aspirin, and 0.035 g of caffeine) for the treatment of colds with a small toxicity. Further addition of a small amount of the chlorpheniramine can produce chlorpheniramine cold tablets which can be applied to the treatment of colds, headache, neuralgia, rheumatism and so on.
Methods of Production
(1) By acetylation reaction from a p-aminophenyl ether. Heat the mixture of benzene, acetic anhydride and amino benzene ether on an oil bath azeotropically for 4h. Then cool the reaction mixture after completion of the reaction, getting precipitate of statins. Filter, washed with cold benzene and then dry to get the final product. The yield usually can reach 86% of the theoretical amount.
(2) By the reaction of sodium ethoxide and acetamidophenol: first add acetamidophenol into sodium ethoxide, and then slowly add ethyl iodide to heat and reflux for 1h, cool, filter, and the dissolve the crude product in ethanol. Filter and dilute the filtrate with water, and then cool, filter, and dried to obtain the final product. The yield can be 80% of the theoretical amount. At the first method, we can also use acetate instead of benzene as the solvent with the following process: heat 40% diluted acetic acid to boiling, add phenetidine and distill off the water. Add acetate when the temperature rise to 150 °C, reflux for 1h and continue to steam until the temperature rises above 150 °C, do sampling for determination of free amino benzene ether. Add certain amount of acetic anhydride based on the amount of residual phenetidine acetic anhydride, and the subject to reflux reaction for another 0.5h. Check the end, and reduce pressure if the product is qualified. Recycle acetate until the product contains 0.046 or less amino content and 0.2% or less acid. Press the reaction mixture back into the hot refined mother liquor, cool the mixture to 40 °C through stirring, filtrate and get the phenacetin crude product. For refining, add boiling water or refined mother liquor to phenacetin crude product, dissolve it through heated stirring, filter, and adjust the filtrate to pH = 4.5-4.7 with acid. Add activated carbon and sodium thiosulfates to stir for bleaching, filter and cool and crystal the filtrate liquid cooling crystallization, apply it to rejection filter, air dried to obtain phenacetin final product.