3,4-Dihydroxybenzoic Acid

3,4-Dihydroxybenzoic Acid

3,4-Dihydroxybenzolic Acid (CAS No.: 99-50-3) is is a natural phenolic compound found in many edible and medicinal plants, that is why it has a common name as Protocatechuic Acid.  


It is not easy to obtain by traditional chemical synthesis, even sometimes it is not recommended in practice due to restriction of enviromental protection. We realized that throught unique and advanced Bio-Synthesis, and make it highly commercialized while cost under control.


Hangzhou Biopak Co., Ltd is known as manufactuer of Phenolic Acids/ Polyphenols manufacturer in China, all based on innovative biosynthesis production process, and our full controlled subsidiary company in Nanchang of Jiangxi Province,  is a modern plant occupying an area of 40,000 sqm.  

Chemical Entity    

protocatechuic acid
Protocatehuic acid
CAS No.: 99-50-3
Formula: C7H6O4
Molecular Weight: 154.12 g/mol
Apparance: White to off-white powder.    


  • This substance or its ester form (Methyl 3,4-Dihydroxy Benzoate, Ethyl 3,4-Dihydroxy Benzoate) is an important key starting material (SM) of Active Pharmaecutical Ingredients (APIs) manufacturing including Gefitinib, Icotinib, Erlotinib, Roflumilast, Itopride, Ethamivan, Mebeverine, Tarceva etc.

  • Ethyl ester of 3,4-Dihydroxybenzoic Acid is approved and listed as FOOD ADDITIVE with sub-classification as antioxidiant by JEFCA/WHO.  

  • It is important intermediate good to the development of chemcial industry.

Important NOTEs

  • We provide esterification reaction to get either Methyl 3,4-Dihydroxy Benzoate or Ethyl 3,4-Dihydroxy Benzoate  for your usage