Pharmaceutical intermediates Paracetamol CAS 103-90-2

Pharmaceutical intermediates Paracetamol CAS 103-90-2

CAS:103-90-2

MF: C8H9NO2

MW:151.16

EINECS:203-157-5

Specification: 99% min Paracetamol

Sample:Paracetamol Powder

Packaging:1kg/bag, 25kg/drum

Brand: Henrikang

Appearance:White

Storage: Cool Dry Place

Shelf Life: 2 Years

Test Method: HPLC

Paracetamol Usage and Synthesis.

Paracetamol acetaminophen through the inhibition of hypothalamic thermoregulation centre prostaglandin synthesis, the role of antipyretic, the strength of its antipyretic effect is similar to aspirin, through the inhibition of central nervous system prostaglandin synthesis and blockade of impulses of the nociceptive nerve endings to produce analgesia, the effect of aspirin is weaker than the aspirin, compared with aspirin, has the advantages of small irritation, rarely allergic reactions, antipyretic and analgesic. The effect is similar to that of finasteride, due to the restriction or prohibition of the use of finasteride in many countries, so that the application of acetaminophen has increased.

Clinically, it is mainly used for cold-induced fever, headache and relief of mild and moderate pain, such as arthralgia, muscle pain, neuralgia, migraine, dysmenorrhoea, cancer pain and post-surgical analgesia, etc.; it can also be used for patients who are allergic to, intolerant of, or unfit for the application of aspirin: such as chickenpox, haemophilia, and other haemorrhagic diseases (including patients with anticoagulant therapy), as well as patients with mild peptic ulcer and gastritis, etc.; in addition, it is also used for patients who are allergic to, or intolerant of, aspirin.

Gastritis patients, etc.; In addition, it can also be used in the synthesis of the drug paracetamol, as well as organic synthesis intermediates, photographic chemicals and hydrogen peroxide stabiliser.

Uses and functions of Paracetamol.

Paracetamol is an antipyretic and analgesic with the international non-proprietary drug name Paracetamol.

It is the most commonly used non-anti-inflammatory antipyretic and analgesic, with antipyretic effects similar to aspirin, weaker analgesic effects, no anti-inflammatory and anti-rheumatic effects, and is the best variety of acetanilide drugs. It is especially suitable for patients who cannot apply carboxylic acid drugs.

Used for colds, toothache and other conditions. Acetaminophen is also an organic synthesis intermediate, stabiliser of hydrogen peroxide, photographic chemicals.

Organic synthesis intermediate, stabiliser of hydrogen peroxide, photographic chemical, non-inflammatory antipyretic and analgesic.

Pharmacological Effect of Paracetamol.

Paracetamol is an antipyretic and analgesic, through the inhibition of cyclooxygenase, selective inhibition of the hypothalamic thermoregulatory centre prostaglandin synthesis, resulting in peripheral vasodilatation, sweating and to achieve the role of antipyretic, its antipyretic effect is similar to the strength of aspirin; through the inhibition of the synthesis and release of prostaglandins, etc., to increase the pain threshold and play an analgesic effect, belong to the peripheral analgesic, the role of the weaker than aspirin, only to light and moderate pain.

It is a peripheral analgesic, weaker than aspirin, and only effective for mild to moderate pain.

Paracetamol has no obvious anti-inflammatory effect.

Product method of Bulk Paracetamol.

It is obtained by acetylation of p-aminophen.

Method 1: add p-aminophenol into dilute acetic acid, then add glacial acetic acid, warm up to 150℃ and react for 7h, add acetic anhydride and react for 2h, check the end point, cool down to 25℃ or below after qualified, shake the filter, wash with water until there is no acetic acid taste, shake dry, and get the crude product.

Method 2: p-aminophenol, glacial acetic acid and acid containing more than 50% of the acid mother liquor together with distillation, evaporation of dilute acid rate of one-tenth of the total amount of distillation per hour, to be the internal temperature rises to 130 ℃ or more, sampling and checking the p-aminophenol residue is less than 2.5%, add dilute acid (content of 50% or more), cooling and crystallisation. Shake filtration, first wash with a small amount of dilute acid, and then wash with a large amount of water until the filtrate is nearly colourless, to get the crude product.

The yield of method 1 is 90%, and the yield of method 2 is 90-95%.

Refining method: put the crude product when the water is heated to nearly boiling. Warm up to full solubility, add activated carbon soaked with water, adjust to pH=4.2-4.6 with dilute acetic acid, boil for 10min.

Pressure filtration, filtrate with a small amount of sodium bisulfite. Cooled to below 20 ℃, precipitated crystals. Shake filtration, washing, drying to get API paracetamol finished product.

Other production methods are: (1) in glacial acetic acid with zinc reduction of p-nitrophenol, at the same time acetylation to get acetaminophen; (2) p-hydroxyacetophenone generated by the hydrazone, placed in the sulfuric acid acid acid solution, add sodium nitrite, transposition to generate acetaminophen