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.
China
