9867. Urea

Nomenclature

CAS number: 57-13-6
Carbamide; carbonyldiamide; Aquacare (Allergan); Aquadrate (Procter & Gamble); Basodexan (Hermal); Hyanit (Wlfer); Keratinamin (Kowa); Nutraplus (Galderma); Onychomal (Hermal); Pastaron (Sato); Ureaphil (Abbott); Urepearl (Otsuka).
CH4N2O; mol wt 60.06.
C 20.00%, H 6.71%, N 46.64%, O 26.64%.

Description and references

Physiological regulator of nitrogen excretion in mammals; synthesized in the liver as an end-product of protein catabolism and excreted in urine. Also occurs normally in skin. First organic compd to be synthesized from inorganic reagents: Whler, Ann. Phys. 12, 253 (1828). Review of mechanism of ammonium cyanate-urea conversion: J. Shorter, Chem. Soc. Rev. 7, 1-14 (1978). Prepn from ammonia, carbon monoxide and sulfur in methanol: Applegath, US 2857430 (1958 to Monsanto); Franz, Applegath, J. Org. Chem. 26, 3304, 3306, 3309 (1961). Review of commercial processes: Faith, Keyes & Clark's Industrial Chemicals, F. A. Lowenheim, M. K. Moran, Eds. (Wiley-Interscience, New York, 4th ed., 1975) pp 854-861; of uses and manufacture: I. Mavrovic, A. R. Shirley, Jr. in Kirk-Othmer Encyclopedia of Chemical Technology vol. 23 (Wiley-Interscience, New York, 3rd ed., 1983) pp 548-575. Review of physiological synthesis: A. J. Meijer in Nitrogen Metabolism and Excretion, P. J. Walsh, P. Wright, Eds. (CRC Press, Boca Raton, 1995) pp 193-204; of analytical methods: A. J. Taylor, P. Vadgama, Ann. Clin. Biochem. 29, 245-264 (1992). Clinical use as emollient: G. Swanbeck, Acta Derm. Venereol. Suppl. 177, 7 (1992). Diagnostic use in Helicobacter pylori infection: A. K. Hamlet et al., Scand. J. Gastroenterol. 30, 1058 (1995).

Chemical structure

Properties

Tetragonal prisms. Develops odor of NH3. Cooling, saline taste. mp 132.7°. On further heating it decomposes to biuret, NH3, and cyanuric acid. d418 1.32; d418 of water solns (w/w): 10% 1.027; 20% 1.054; 50% 1.145. pH of a 10% water soln: 7.2. One gram dissolves in 1 ml water, 10 ml 95% alc, 1 ml boiling 95% alc, 20 ml abs alc, 6 ml methanol, 2 ml glycerol. Almost insol in chloroform, ether. Sol in concd HCl. Water solns hydrolyze slowly to ammonium carbonate with eventual decomp to ammonia and carbon dioxide.

Derivative

Hydrochloride.

Nomenclature

CAS number: 506-89-8
CH4N2O.HCl; mol wt 96.52.
C 12.44%, H 5.22%, N 29.02%, O 16.58%, Cl 36.73%.

Properties

White to faintly yellow, deliquesc crystals. Dec at 145°. Sol in water.

Use

Nitrogen-release fertilizer. Starting material for resins and plastics. Condensed with malonic ester to form barbituric acid. Used in the manuf of paper. Analytical use in buffer solns.

Therapeutic Category

Emollient; diuretic.

Therapeutic Category (Veterinary)

Nutritional factor (partial source of dietary nitrogen in ruminants); debriding agent; diuretic.

Keywords

Diuretic