Salicylic acid

Introduction:

English name: Salicylic acid

English alias: o-hydroxybenzoic acid, 2-hydroxybenzoic acid

Appearance: white crystalline powder

Relative molecular mass: 138.122

CAS RN: 69-72-7

EINECS number: 200-712-3

Molecular formula: C7H6O3

Boiling point: 336.3 ℃

Density: 1.375 g/cm³

Solubility: slightly soluble in cold water, easily soluble in hot water, ethanol, ether and acetone, soluble in hot benzene.

Content: ≥99% (HPLC)

Salicylic acid is an organic acid with the chemical formula C7H6O3. It is a white crystalline powder, slightly soluble in cold water, easily soluble in hot water, ethanol, ether and acetone, soluble in hot benzene. It is mainly used as an important raw material for fine chemicals such as medicine, fragrance, dye, pesticide, rubber additives, etc. As a precursor of aspirin (acetylsalicylic acid) and a plant hormone, salicylic acid occurs naturally in a variety of plants, especially in the bark of willow trees. It is mainly produced by a synthetic process from phenol and carbon dioxide. Modern production is obtained by reacting dried sodium phenolate (sodium phenolate) with carbon dioxide and then treating it with acid.

Salicylic acid is widely used in skin care products for its exfoliating, antibacterial and antifungal properties in the treatment of acne, dandruff, psoriasis, and symptoms of excessive keratin proliferation (such as keratosis, warts and chicken skin). In addition, salicylic acid is also used as a food preservative, bactericide and antimicrobial agent. Although low concentrations of salicylic acid products are generally considered safe, high concentrations of salicylic acid can cause minor chemical burns and may lead to dangerous poisoning if ingested, so safety precautions are required when using it.

Synthesis

1. Salicylic acid can be synthesized from phenylalanine in organisms.

2. The industrial production of salicylic acid is to synthesize the sodium salt of salicylic acid by using phenol and carbon dioxide at high temperature (390K) and high pressure (100 atmospheres) through the Kolber-Schmidt reaction, and then obtain salicylic acid by acidification with sulfuric acid.

3. Salicylic acid can also be obtained by hydrolyzing aspirin (acetylsalicylic acid) or methyl salicylate.

Uses

Salicylic acid, also known as o-hydroxybenzoic acid, is an important raw material for organic synthesis. In pesticide production, it is used to synthesize isopropyl salicylate, an intermediate of organophosphorus insecticides isothiocarb and methyl isofenphos, and 4-hydroxycoumarin, an intermediate of rodenticides warfarin and coumarin; in the pharmaceutical industry, salicylic acid is used as an intermediate of acetylsalicylic acid (aspirin) and many other drugs in addition to being used as a disinfectant and preservative; it is also an important raw material for dyes, fragrances, rubber and other industries. Uses: It is mainly used as a raw material for aspirin and pesticides such as isocarbophos. It can also be used in the dye industry and refined chemical reagents.

Uses

It is used in the pharmaceutical industry to make antipyretic, analgesic, anti-inflammatory, diuretic and other drugs. It is used in the dye industry to make azo direct dyes and acid mordant dyes. It is also used in spices.

Uses

Salicylic acid is an important raw material for fine chemicals such as medicines, spices, dyes, rubber additives, etc. In the pharmaceutical industry, salicylic acid itself is used as a disinfectant and preservative for local keratin hyperplasia and fungal infections of the skin. As a Chemicalbook intermediate in medicine, it is used in the production of painkillers, urea, acetylsalicylic acid (aspirin), sodium salicylate, salicylamide, glyburide, niclosamide, phenyl salicylate, ethyl parahydroxybenzoate, bismuth subsalicylate, sulfasalazine and other drugs. In the dye industry, it is used to produce dyes such as direct yellow GR, direct fast gray BL, direct fast brown RT, acid mordant brown G, acid mordant yellow GG. Various esters of salicylic acid can be used as fragrances, such as methyl salicylate, which can be used as oral fragrances for toothpaste, other flavorings and food fragrances. In the rubber industry, it is used to produce anti-scorching agents, ultraviolet absorbers and foaming aids. Salicylic acid can also be used as a curing agent for phenolic resins, a slurry preservative for textile printing and dyeing, and a swelling agent (dyeing accelerator) for synthetic fiber dyeing.

Uses

Anti-inflammatory inhibitor of cyclooxygenase activity. Determination of aluminum, boron, cerium, copper, iron, lead, manganese, mercury, silver, titanium, tungsten, vanadium, hyposulfite, nitrate and nitrite. Precipitating thorium separates thorium from cerium and other rare earth elements, separates zirconium from titanium, fluorescent indicator, preservative, complex indicator.