Chinese name: Salicylic acid

English name :Salicylic acid

CAS:69-72-7

EINECS number :200-712-3

Molecular formula :C7H6O3

MDL number :MFCD00002439

Molecular weight :138.12

Appearance: white acicular crystal or hairy crystalline powder.

Appearance: white acicular crystal or monoclinic prism, spicy taste. Slightly soluble in water, soluble in acetone, turpentine, ethanol, ether, benzene and chloroform.

Solubility: soluble in water, soluble in ethanol, ether, chloroform.

Melting point :158-161 °C(lit.)

Boiling point :211 °C(lit.)

Density :1.44

Vapor density :4.8 (vs air)

Vapor pressure :1 mm Hg (114 °C)

FEMA:3985

Refractive index :1,565

Flash point :157 °C

Storage :Store at RT.

ethanol: 1 M at 20 °C, clear, colorless

Acidity coefficient (pKa):2.98(at 25℃)

Form: solid

Color: White to off-white

PH value :2.4 (H2O)(saturated solution)

Odor :at 100.00 %. faint phenolic nutty

ph range :Non0 uorescence (2.5) to dark blue 0 uorescence (4.0)

Fragrance :nutty

Water solubility: 1.8g /L (20 oC)

Sensitivity: light sensitive

Maximum wavelength (λmax):210nm, 234nm, 303nm

JECFA Number:958

Merck: 14833 2

Detection methods :HPLC,NMR

Sublimation point :70 oC

BRN:774890

Use 1

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

Preparation method

Method one

It is prepared by carboxylation of sodium phenol with carbon dioxide and then acidification.

Using phenol and liquid caustic soda to make sodium phenol salt solution, vacuum drying, and then slowly into the dry carbon dioxide at 100℃, when the pressure reaches 0.7 ~ 0.8MPa, stop the carbon dioxide, temperature rise to 140 ~ 180℃. After the reaction is completed, add water to dissolve sodium salicylate for decolorization and filtration, and then add sulfuric acid acidification, that is, salicylic acid is precipitated, and the finished product is obtained through filtration, washing and drying.