Catalog Number
ACM150130-2
Product Name
Aminobenzoic Acid, USP
Category
Liquid Crystal (LC) Building Blocks
Description
P-aminobenzoic acid appears as colorless crystals that discolor on exposure to light and air. (NTP, 1992);Solid
IUPAC Name
4-aminobenzoic acid
Molecular Weight
137.14g/mol
Molecular Formula
C7H7NO2;C7H7NO2
Canonical SMILES
C1=CC(=CC=C1C(=O)O)N
InChI
InChI=1S/C7H7NO2/c8-6-3-1-5(2-4-6)7(9)10/h1-4H,8H2,(H,9,10)
InChI Key
ALYNCZNDIQEVRV-UHFFFAOYSA-N
Melting Point
370 to 372 °F (NTP, 1992);188.5 °C;188.5 °C;188.5°C
Solubility
0.04 M;In water, 5,390 mg/L at 25 °C; 6,110 mg/L at 30 °C;One gram dissolves in 90 mL boiling water; in 8 ml alcohol, in 60 mL ether. Soluble in ethyl acetate, glacial acetic acid; slightly soluble in benzene; practically insoluble in petroleum ether.;Freely soluble in alcohol;Soluble in alkalis and ethane (C2H6);Soluble in oxygenated solvents;Soluble in ethanol and ether; slightly soluble in acetone; insoluble in chloroform and benzene;Solubility in 90% ethanol, 11.3% at 9.6 °C; solubility in benzene, 0.06% at 11 °C;The solubility of 4-aminobenzoic acid is 6.1 g/L at 30 °C in water, 125 g/L alcohol and 17 g/L ether; it is soluble in ethyl acetate and glacial acetic acid, slightly soluble in benzene, and practically insoluble in petroleum ether.;6.11 mg/mL;>20.6 [ug/mL]
Application
Aminobenzoic Acid, USP serves multiple purposes due to its versatile chemical properties. This organic compound, structurally known as para-aminobenzoic acid (PABA), is recognized for its light absorption throughout the UVB range, making it a valuable ingredient in sunscreen products. PABA, naturally occurring in colorless needle-like crystal form, can turn light yellow upon exposure to air or light. It is soluble in various solvents such as hot water and ethanol but remains insoluble in water and benzene. In the medical field, it plays a crucial role in synthesizing folic acid by combining with pteridine and glutamic acid, and it is used in certain medicines, including analgesic or anesthetic preparations. Additionally, the potassium salt derivative of PABA is employed as a treatment for fibrotic skin disorders like Peyronie's disease. It also holds significance in nutritional studies where it helps assess the accuracy of 24-hour urine collection. Apart from its role in human health, PABA is also a metabolite in both Escherichia coli and plants, highlighting its broad biological relevance.
Color/Form
Monoclinic prisms from dilute alcohol;Light buff crystals; white when pure;Yellowish to red crystals or prisms;White or slightly yellow crystals or crystalline powder
Covalently-Bonded Unit Count
1
Exact Mass
137.047678g/mol
Log P
0.83 (LogP);log Kow = 0.83;0.83
MeSH Entry Terms
4 Aminobenzoic Acid;4 Aminobenzoic Acid, Potassium Salt;4-Aminobenzoate, Potassium;4-Aminobenzoic Acid;4-Aminobenzoic Acid, Potassium Salt;Aminobenzoate, Potassium;Aminobenzoic Acid (USP);Epit Vit;Epitelplast;Hachemina;Magnesium para-Aminobenzoate;p Aminobenzoic Acid;p-Aminobenzoic Acid;PABA;Pabasan;para Aminobenzoic Acid;para-Aminobenzoate, Magnesium;para-Aminobenzoic Acid;Paraminan;Paraminol;Potaba;Potassium 4 Aminobenzoate;Potassium 4-Aminobenzoate;Potassium Aminobenzoate
Monoisotopic Mass
137.047678g/mol
Other Experimental
May turn slightly yellow on prolonged exposure to light and air;Henry's Law constant = 1.5X10-10 atm-cu m/mole at 25 °C (est);Hydroxyl radical reaction rate constant = 4.0X10-11 cu cm/molecule sec at 25 °C (est)
Stability
Chemical stability: Stable under recommended storage conditions.;Conditions to avoid: Exposure to light. May discolor on exposure to air and light.
Vapor Pressure
4.5X10-6 mm Hg at 25 °C /Extrapolated from measurements at higher temperatures/