Chemical Properties
White rhomboidal crystals, decompose when exposed to light. Soluble in ether and isopropanol, soluble in ethanol and water; R-form melting point is 133°C, [α]-159.73° (ethanol), gradually racemic at 160°C. S-form melting point is 133.8°C, [α]+156.57° (water).
Uses
Organic synthesis, medicine (urinary antiseptic).
Uses
DL-Mandelic acid may be used as an analytical reference standard for the determination of DL-mandelic acid in:
Human urine samples by high performance liquid chromatography (HPLC) equipped with ultraviolet (UV) detector.
Rat urine samples by gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring (SIM) detection.
Preparation
Mandelic acid can be prepared by the hydrolysis of amygdalin with sulfuric acid or of mandelonitrile with hydrochloric acid. The mandelonitrile can be prepared by the action of hydrocyanic acid on benzaldehyde, and by the action of sodium or potassium cyanide on the sodium bisulfite addition product of benzaldehyde. The procedure described differs from earlier methods in that the sodium bisulfite addition compound of benzaldehyde is prepared in the presence of sodium cyanide and the nitrile is formed immediately.
synthesis of mandelic acid
Definition
ChEBI: Mandelic acid is a 2-hydroxy monocarboxylic acid that is acetic acid in which two of the methyl hydrogens are substituted by phenyl and hydroxyl groups. It has a role as an antibacterial agent and a human xenobiotic metabolite. It is a 2-hydroxy monocarboxylic acid and a member of benzenes. It derives from an acetic acid. It is a conjugate acid of a mandelate. Exists in stereoisomeric forms. The properties are those of the dl-form.
General Description
DL-Mandelic acid is an aromatic hydrocarbon metabolite of styrene.
Hazard
Toxic by ingestion.
Flammability and Explosibility
Not classified
Safety Profile
Poison by
intramuscular route. Moderately toxic by
ingestion. Continued absorption can cause
kidney irritation. When heated to
decomposition it emits acrid smoke and
irritating fumes.
