Undecylenic Acid or Undecenoic Acid is an organic compound with the formula CH2=CH(CH2)8CO2H. It is an unsaturated fatty acid. It is a colorless oil. Undecylenic acid is used for the treatment of fungal infections of the skin, but it is also a precursor in the manufacture of many pharmaceuticals, personal hygiene products, cosmetics, and perfumes. Undecylenic acid or Undecenoic Acid is an active ingredient in medications for skin infections, and to relieve itching, burning, and irritation associated with skin problems. For example, it is used against fungal skin infections. Undecylenic acid has been used as a linking molecule.
C11H20O2 --- 184.28
10-Undecenoic acid.
10-Undecenoic acid --- [112-38-9].
Undecylenic Acid contains not less than 97.0 percent and not more than 100.5 percent of C11H20O2.
Packaging and storage: Preserve in tight, light-resistant containers.
Identification:
A: To 1 mL add potassium permanganate, dropwise: the permanganate color is discharged.
B: Place 3 mL of it and 3 mL of freshly distilled aniline in a tall test tube, and heat for 10 minutes at a rate such that the ring of condensate remains just below the mouth of the tube. Cool, add 10 mL of alcohol and 10 mL of ether, and transfer to a separator. Wash the ether solution with four 20-mL portions of water and discard the water washings. Heat on a steam bath until the odor of ether no longer is perceptible, then add a few mg of activated carbon, mix, and filter. Evaporate the filtrate nearly to dryness, and recrystallize the residue from 70 percent alcohol: the anilide so obtained melts between 66 and 67.5 .
Specific gravity: between 0.910 and 0.913.
Congealing range: not lower than 21 .
Refractive index: between 1.447 and 1.448.
Residue on ignition: not more than 0.15%.
Water-soluble acids: Shake 5 mL with 5 mL of water, and filter the water layer through a filter paper previously moistened with water. Add 1 drop of methyl orange, and titrate with 0.01 N sodium hydroxide: not more than 1.0 mL of 0.010 N sodium hydroxide is required to match the color produced by 1 drop of methyl orange in 5 mL of water.
Heavy metals: 0.001%.
Iodine value: between 131 and 138.
Assay: Dissolve about 750 mg of Undecylenic Acid, accurately weighed, in 50 mL of alcohol, add 3 drops of phph, and titrate with 0.1 N sodium hydroxide to the first pink color that persists for not less than 30 seconds. Perform a blank determination and make any necessary correction. Each mL of 0.1 N sodium hydroxide is equivalent to 18.43 mg of C11H20O2.
C11H20O2 --- 184.3 --- 112-38-9
DEFINITION
Undec-10-enoic acid.
Content: 97.0 per cent to 102.0 per cent.
CHARACTERS
Appearance: White or very pale yellow, crystalline mass or colourless or pale-yellow liquid.
Solubility: Practically insoluble in water, freely soluble in ethanol (96 per cent) and in fatty and essential oils.
IDENTIFICATION
A. Refractive index: 1.447 to 1.450, determined at 25 ± 0.5C.
B. Freezing point: 21C to 24C.
C. To 2.0 g add 2 mL of freshly distilled aniline and boil under a reflux condenser for 10 min. Allow to cool and add 30 mL of ether. Shake with 3 quantities, each of 20 mL, of dilute hydrochloric acid and then with 20 mL of water. Evaporate the organic layer to dryness on a water-bath. After re-crystallising twice from ethanol (70 per cent V/V) and drying in vacuo for 3 h, the residue melts at 66C to 68C.
D. Dissolve 0.1 g in a mixture of 2 mL of dilute sulfuric acid and 5 mL of glacial acetic acid. Add dropwise 0.25 mL of potassium permanganate solution. The colour of the potassium permanganate is discharged.
TESTS
Peroxide value: Maximum 10.
Fixed and mineral oils: To 1.0 g add 5 mL of sodium carbonate solution and 25 mL of water and boil for 3 min. The hot solution is not more opalescent than reference suspension.
Water-soluble acids: To 1.0 g add 20 mL of water heated to 35-45C and shake for 2 min. Cool and filter the aqueous layer through a moistened filter. To 10 mL of the filtrate add 0.1 mL of phph solution. Not more than 0.1 mL of 0.1 M sodium hydroxide is required to change the colour of the indicator.
Degree of unsaturation: Dissolve 85.0 mg in a mixture of 5 mL of dilute hydrochloric acid and 30 mL of glacial acetic acid. Using 0.05 mL of indigo carmine solution as indicator, added towards the end of the titration, titrate with0.0167 M bromide-bromate until the colour changes from blue to yellow. 8.9 mL to 9.4 mL of0.0167 M bromide-bromate is required. Carry out a blank titration.
Sulphated ash: Maximum 0.1 per cent, determined on 0.50 g.
