3,4-Dihydroxybenzoic acid

CAS	99-50-3
Structure
Synonyms	Protocatechuic acid
IUPAC Name	3,4-Dihydroxybenzoic acid
Molecular Weight	154.12
Molecular Formula	C7H6O4
Canonical SMILES	C1=CC(=C(C=C1C(=O)O)O)O
InChI	InChI=1S/C7H6O4/c8-5-2-1-4(7(10)11)3-6(5)9/h1-3,8-9H,(H,10,11)
InChI Key	YQUVCSBJEUQKSH-UHFFFAOYSA-N
Melting Point	197-200 °C (dec.)(lit.)
Purity	98%
Density	1.54 g/ml
pKa	4.48
pH	3.78 (1 mM solution)
Solubility in Water	20 g/L
Appearance	Beige to brown solid