4-Aminobenzoic acid

4-Aminobenzoic acid
	C=black, H=white, O=red, N=blue
Names
	Preferred IUPAC name 4-Aminobenzoic acid
	Other names para-Aminobenzoic acid; p-Aminobenzoic acid; PABA; Vitamin B10; Vitamin Bx; Bacterial vitamin H1
Identifiers
CAS Number	150-13-0 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:30753 ;
ChEMBL	ChEMBL542 ;
ChemSpider	953 ;
DrugBank	DB02362 ;
ECHA InfoCard	100.005.231
KEGG	D02456 ;
PubChem CID	978;
UNII	TL2TJE8QTX ;
CompTox Dashboard (EPA)	DTXSID6024466 ;
	InChI InChI=1S/C7H7NO2/c8-6-3-1-5(2-4-6)7(9)10/h1-4H,8H2,(H,9,10) Key: ALYNCZNDIQEVRV-UHFFFAOYSA-N ; InChI=1/C7H7NO2/c8-6-3-1-5(2-4-6)7(9)10/h1-4H,8H2,(H,9,10) Key: ALYNCZNDIQEVRV-UHFFFAOYAH;
	SMILES O=C(O)c1ccc(N)cc1;
Properties
Chemical formula	C7H7NO2
Molar mass	137.138 g·mol−1
Appearance	White-grey crystals
Density	1.374 g/mL
Melting point	187 to 189 °C (369 to 372 °F; 460 to 462 K)
Boiling point	340 °C (644 °F; 613 K)
Solubility in water	1 g/170 mL (25 °C); 1 g/90 mL (90 °C)
Acidity (pKa)	2.42 (amino; H2O); 4.88 (carboxyl; H2O);
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	eye irritant, some persons may be allergic to this compound
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

4-Aminobenzoic acid (also known as para-aminobenzoic acid or PABA because the two functional groups are attached to the benzene ring across from one another in the para position) is an organic compound with the formula H₂NC₆H₄CO₂H. PABA is a white solid, although commercial samples can appear gray. It is slightly soluble in water. It consists of a benzene ring substituted with amino and carboxyl groups. The compound occurs extensively in the natural world.

^ van de Graaf, Bas (1981). "Substituent effects. 7. Microscopic dissociation constants of 4-amino- and 4-(dimethylamino)benzoic acid". J. Org. Chem. 46 (4): 653–657. doi:10.1021/jo00317a002.
^ Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. pp. 5–89. ISBN 978-1-4987-5428-6.

[1] van de Graaf, Bas (1981). "Substituent effects. 7. Microscopic dissociation constants of 4-amino- and 4-(dimethylamino)benzoic acid". J. Org. Chem. 46 (4): 653–657. doi:10.1021/jo00317a002.

[CRC97-2] Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. pp. 5–89. ISBN 978-1-4987-5428-6.

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