4-Acetamidophenol,CAS 103-90-2

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 Use and Manufacturing
Methods of Manufacturing
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.
Uses
1. Antiinfectant
2. Dispersing agent in liquid scintillation counting
3. Analgesic; antipyretic