Introduction to 3,5-dihydroxybenzoic acid

3,5-dihydroxybenzoic acid, alias α- Rezocinic acid, white or light pink acicular crystal. Soluble in ethanol, ether, acetone and hot water, it reacts with fuming sulfuric acid or hot concentrated sulfuric acid to form purplish red compounds, and reacts with ferric chloride to show grape wine color. It is mainly used as an intermediate in organic synthesis, pharmaceuticals, synthetic resins, etc.

Chinese Name: 3,5-dihydroxybenzoic acid

English Name: 3,5-dihydroxybenzoic acid

Molecular formula: c7h6o4

Properties: This product is a white crystalline powder, which is easily soluble in alcohol, ether and hot water. It will turn pink when encountering ferric chloride.

Molecular structure data

Molar refractive index: 36.94

Molar volume (m3/mol): 98.8

Isotonic specific volume (90.2k): 299.4

Surface tension (dyne/cm): 84.2

Polarizability: 14.64

synthetic method

It is obtained from benzoic acid through sulfonation, alkali melting and acidification. Benzoic acid is sulfonated with fuming sulfuric acid at 240~250 ℃ for 5h to produce 3,5-disulfonic benzoic acid, which is then alkali melted with sodium hydroxide at 300 ℃. The reaction product sulfuric acid is neutralized to weak alkalinity, filtered and concentrated, acidified to weak acidity, and extracted with ether. The crude product obtained by recovering ether from the extract is recrystallized with water to obtain the finished product.

Storage method

Store in a cool and ventilated warehouse. Keep away from fire and heat source. Package sealing. It shall be stored separately from oxidant and strong alkali, and mixed storage shall not be allowed. Fire fighting equipment of corresponding varieties and quantities shall be provided. The storage area shall be equipped with appropriate materials to contain the leakage.