What Is Phenacetin?

Phenacetin (or Phenacetin), chemical formula C10H13NO2, is a white crystalline solid at room temperature with a melting point of about 134 ° C. It is a banned drug in many countries.

Drug Name: Phenacetin
Alias: Phenacetin

Foreign name: Phenacetin
Athletes use with caution: Use with caution
Whether to include health insurance: Not included

Phenacetin

Chinese name:

Chinese alias: Finacetin; Finacetin;

English name: phenacetin

English alias: p-Acetophenetidide; Acetamide, N- (4-ethoxyphenyl)-; Achrocidin; p-ethoxyacetanilide; Codempiral;

CAS number: 62-44-2

Molecular formula: C10H13NO2

Molecular weight: 179.21600

Exact mass: 179.09500

PSA: 38.33000

LogP: 2.11670

Physical and chemical properties of phenacetin

Appearance and properties: white crystalline powder

Density: 1.099 g / cm3

Melting point: 133-136 ° C (lit.)

Boiling point: 132 ° C / 4mmHg

Refractive index: 1.505 (20ºC)

Water solubility: 0.076 g / 100 mL

Stability: Stable. Incompatible with strong oxidizing agents, strong acids.

Storage conditions: storeroom is ventilated, low-temperature and dry, and stored separately from reducing agents and food additives ^[1]

Phenacetin chemical properties

White shiny scaly crystal or white crystalline powder. The melting point is 137-138 ° C and the refractive index is 1.571. Insoluble in water, slightly soluble in ether, slightly soluble in boiling water, soluble in ethanol and chloroform. It does not show color when dissolved in concentrated sulfuric acid. It is orange yellow after adding nitric acid to the solution. Odorless and slightly bitter.

Phenacetin molecular structure data

1. Molar refractive index: 51.83

2. Molar volume (m3 / mol): 163.0

3. Isotonic specific volume (90.2K): 407.4

4. Surface tension (dyne / cm): 39.0

5. Polarizability (10-24cm3): 20.54

Computational chemical data for phenacetin

1. Hydrophobic parameter calculation reference value (XlogP): None

2.Number of hydrogen-bonded donors: 1

3.Number of hydrogen bond acceptors: 2

4.Number of rotatable chemical bonds: 3

5.Number of tautomers: 3

6. Topological molecular polar surface area 38.3

7.Number of heavy atoms: 13

8.Surface charge: 0

9.Complexity: 162

10.Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 0

13. Determine the number of chemical bond stereocenters: 0

14. Uncertain number of chemical bond stereocenters: 0

15. Number of covalent bond units: 1 ^[2]

Production method of phenacetin

(1) Obtained by acetylation of p-aminophenyl ether. The mixture of benzene, acetic anhydride and p-aminophenyl ether was azeotropically heated on an oil bath for 4 h. After the reaction was completed, the reactant was cooled, that is, phenatin was precipitated, filtered, washed with cold benzene, and dried to obtain the yield. The theoretical amount 86%.

(2) Obtained by the action of acetaminophen and sodium ethoxide: firstly add p-acetamidophenol to sodium ethoxide, then slowly add iodoethane, heat to reflux for 1 h, cool, and filter, and the obtained crude product is dissolved in ethanol. Filtration, the filtrate is diluted with hot water, and then cooled, filtered, and dried to obtain the finished product, the yield is 80% of the theoretical amount. The first method can also use acetic acid instead of benzene as the solvent. The process is as follows. Heat 40% dilute acetic acid to boiling, add p-aminophenyl ether, and evaporate the water. When the temperature rises to 150 ° C, add glacial acetic acid, reflux for 1h, continue to steam, and wait for the temperature to rise above 150 ° C. Take a sample to determine the free aminobenzene. Diethyl ether, add acetic anhydride according to the residual amount of aminophenyl ether, react at reflux for 0.5h, check the end point, reduce the pressure after passing, recover the acetic acid to the amino content below 0.046 and the acid content below 0.2%, and press the reaction into the hot refined mother liquor. Stir to 40 ° C and filter to obtain crude phenacetin. Refined, crude finacetin plus boiling water or refined mother liquor, heated and dissolved to dissolve, filtered, the filtrate was adjusted to pH = 4.5-4.7 with acid, activated carbon and sodium thiosulfate were added to stir and decolorize, filtered, the filtrate was cooled to crystallize, shake filtered, air flow Dry to get phenacetin. ^[3]

Phenoxetine related drug information

Phenacetin classification name

First level classification: Nervous system drugs Second level classification: Antipyretic analgesics Third level classification:

English name of phenacetin drug

Phenacetin

Phenacetin drug alias

Paracetamol, Acetohenetidin

Phenacetin drug dosage form

See dosage and usage.

Phenacetin pharmacological action

It has antipyretic and analgesic effects, but has no anti-inflammatory and anti-rheumatic effects.

Phenacetin pharmacokinetics

This product is mainly metabolized into acetaminophen in the liver, and a small part is deacetylated to form p-aminophenyl ether, which can be further metabolized to iminoquinone to oxidize hemoglobin to methemoglobin, and cyanosis may occur when the amount is large, even severe Hypoxia symptoms are more common in children.

Phenacetin indication

This product is mainly used for antipyretic and analgesic purposes. Due to its high toxicity, it has been replaced by acetaminophen. It is only used in some compound preparations.

Phenacetin contraindications

1. Allergic to this product, pregnant women, breast-feeding are prohibited; 2. Liver and renal insufficiency are prohibited; 3. People with a history of hemolytic disease or other blood diseases are prohibited; 4. The elderly and children should be used with caution.

Finacetin precautions

Sealed and protected from light.

Phenacetin adverse reactions

This product is relatively toxic. Long-term or excessive application can cause hemolytic anemia, methemoglobinemia, renal papillary necrosis and renal pelvis metastatic cell carcinoma.

Phenacetin dosage

1. Compound Pelmin tablets (Pelmin cold tablets): Each tablet contains 0.162g of phenacetin, 0.002g of pirmin, 0.2268g of aspirin, 0.0324g of caffeine, 1 to 2 tablets per time, 3 times / d. 2. Somidon tablets (Somedon): Each tablet contains 0.15 g of aminopyrine, 0.2 g of phenacetin, 0.015 g of phenobarbital, and 0.05 g of caffeine. It is used for headache, toothache, arthralgia or dysmenorrhea, etc. Orally, 1 tablet once if necessary.

Fenacetin drug evaluation

Antipyretic analgesics, used to treat fever headache, neuralgia, etc. Antipyretic effect is stronger than analgesic effect. The strength of the drug is equivalent to that of aspirin, its effect is slow and long-lasting, and its toxicity is low. Studies have shown that paracetamol and its metabolites have antipyretic effects. Because fenacetin cannot be converted to paracetamol with an enzyme inhibitor, it can still show a significant antipyretic effect. Therefore, the antipyretic effect that appears after giving thread products is not only caused by its active product, paracetamol. The mild analgesic effect of phenacetin can generally be maintained for 3-4 hours; the synergistic effect with salicylic acid can enhance the analgesic effect. Clinically, it is mainly used for antipyretic and analgesic in small animals. This product is also a component of APC tablets. ^[4]