Acetaminophen

Acetaminophen, also known by its common name paracetamol, is a widely utilized medication that serves as an effective analgesic, which means it alleviates pain, and an antipyretic, which refers to its ability to reduce fever. This compound is characterized by its chemical formula C8H9NO2. It is one of the most popular and frequently used over-the-counter drugs available on the market today, and it comes in a variety of formulations to suit different needs and preferences. These formulations can include tablets, capsules, syrups, and even suppositories, making it accessible and convenient for individuals seeking relief from minor aches and pains or the discomfort of fever.

Acetaminophen differs from the nonsteroidal anti-inflammatory agents described in that it is devoid of anti-inflammatory and antirheumatic properties. It was recently shown that acetaminophen, like aspirin, inhibits cyclooxygenase action in the brain and is even stronger than aspirin. On the other hand, the mechanism of analgesic action of acetaminophen is not fully clear, since it acts poorly on peripheral cyclooxygenase.

Acetaminophen is an analgesic and antipyretic compound. Unlike many NSAIDs, which inhibit both COX-1 and COX-2, early studies suggested that acetaminophen is a poor inhibitor of both isoforms. However, it does inhibit COX-2 by 83% and COX-1 by 56% in human bloodex vivo, albeit at a high 1,000 mg dose, with IC50values of 25.8 and 113.7 μM, respectively. Acetaminophen is enzymatically and non-enzymatically converted to several reactive metabolites that contribute to adverse or indirect effects, including liver injury. At toxic doses, the acetaminophen metabolite N-acetyl-4-benzoquinone imine (NAPQI; ) depletes glutathione reserves in the liver, leading to an accumulation of NAPQI and subsequent hepatocyte necrosis. Acetaminophen decreases glutathione levels and reduces glutathione peroxidase activity in mice when administered at a dose of 250 mg/kg and induces ferroptotic cell death in primary mouse hepatocytes, an effect that can be blocked by the ferroptosis inhibitor ferrostatin-1 . Acetaminophen has analgesic and antipyretic properties in animal models.

White Solid

Acetaminophen was first discovered by H. N. Morse in 1878. Although many studies on its use as an analgesic were performed, it wasn’t until 1950 that it was marketed under the name Triagesic. Today, its most common trade names are Tylenol and Panadol, but a large percentage of its sales are as a generic drug. It is the most commonly used medication for pain and fever in both the United States and Europe. It is on the World Health Organization's List of Essential Medicines.

P-aminophenol acetylation
Method 1: adding p-aminophenol into dilute acetic acid, adding glacial acetic acid, heating to 150 ℃ for 7h, adding acetic anhydride and then reacting for 2h, checking the end point, cooling to below 25 ℃, filtering, Sour, dry, too crude.
Method 2: p-aminophenol, glacial acetic acid and acid containing more than 50% acid mother liquor distillation, steaming out the rate of dilute acid per hour of the total amount of distillate
First, wait until the temperature rose to 130 ℃ above, the sampling of para-aminophenol residues less than 2.5%, adding dilute acid (50% or more), cooling crystallization. Rejection filter, first with a small amount of dilute acid washing, then a large number of washed to the filtrate close to colorless, too crude.
The yield of Method 1 was 90%
The yield of Method 2 was 90-95%. Refining method: the water heated to near boiling when the crude input. Warm to the whole solution, add water soaked activated carbon, with dilute acetic acid adjusted to pH = 4.2-4.6, boiling 10min. Pressure filtration, the filtrate plus a small amount of sodium sulfite. Cooled to 20℃ or less, crystallization. Rejection filter, washed, dry raw material drug paracetamol finished. Other production methods are:
(1) reduction of p-nitrophenol with zinc in glacial acetic acid, and acetylation to obtain acetaminophen; (2) p-hydroxy acetophenone generated hydrazone, sulfuric acid in acidic solution, adding sodium nitrite, translocation to generate acetaminophen.

1. Antiinfectant
2. Dispersing agent in liquid scintillation counting
3. Analgesic; antipyretic

Analgesic; antipyretic

antiinfectant

manufacture of azo dyes, photographic chemicals.

Acetaminophen is widely used as an analgesic and fever-reducing agent. Acetaminophen is designed for moderate analgesia. It is also effective like aspirin and is used in analgesia for headaches (from weak to moderate pain), myalgia, arthralgia, chronic pain, for oncological and post-operational pain, etc.

Molecular Weight:151.16
XLogP3:0.5
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:151.063328530
Monoisotopic Mass:151.063328530
Topological Polar Surface Area:49.3
Heavy Atom Count:11
Complexity:139
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes