Carbamides

Dormex. Dormex [156-62-7] (Alzodep, hydrogen cyanamide) (26) should not be confused with the same term used for calcium cyanamide. Its other names include carbamide, cyanogenamide, and amidocyanogen. The compound is easily prepared by the continuous carbonation of calcium cyanamide in water (see Cyanamides). 

Urea peroxohydrate is made commercially by Solvay Deutschland, Degussa (Germany), and Mitsubishi Gas Chemical. It is known commercially as urea hydrogen peroxide, hydrogen peroxide carbamide, Exterol, Hydroperit, Hydroperit, Hyperol, Orti2on, Percarbamid, Percarbamide, Perhydrit, Perhydrol-Urea, Thenardol, and UHP. In 1994 the U.K. price was J7—8/kg ( 10—12/kg). World production in 1993 was several hundred metric t. 

Urea. Urea (carbamide) CH4N2O, is the most important building block for amino resins because urea—formaldehyde is the largest selling amino resin, and urea is the raw material for melamine, the amino compound used in the next largest selling type of amino resin. Urea is also used to make a variety of other amino compounds, such as ethyleneurea, and other cyclic derivatives used for amino resins for treating textiles. They are discussed later. 

Carbamic acid is the monoamide of carbonic acid the diamide is the weU-known compound urea [57-13-6] also called carbamide (see Urea). Guanidine [113-00-8] could be regarded as the amidine of carbamic acid (see Cyanamides). 

CARBAMIC ACID, ETHYL ESTER see URETHANE CARBAMIDE, THIO- see THIOUREA... 

Chemical Designations - Synonyms Carbamide, Carbonyldiamide Chemical Formula NHjCONHj Observable Characteristics - Physical State (as normally shipped) Solid Color White Odor Odorless, or slight ammonia odor. 

Chemical Designations - Synonyms Carbamide peroxide, Carbonyldiamine, Hydrogen peroxide carbamide, Percarbamide, Perhydrol-Urea, Urea hydrogen peroxide Chemical Formula ... 

Frerichs found that berberinium chloride, when fused with carbamide at 200° or heated in a current of carbon dioxide at 190°, was converted into berberrubine, CigHig04N. OHjO, dark red leaflets or needles, m.p. 285°, which regenerated berberinium iodide on treatment with methyl iodide. 

EtOH), was prepared via the carbamide. Dendrobine has also been prepared by Chen and Chen, who record for certain of the salts, m.ps. different from those given above, e.g., B. HCl, m.p. 193°, B. HI, m.p. 284-5°, but whose data are otherwise in agreement with those of Suzuki et al. 

Ultraviolet and infrared spectroscopic investigations and also chemical behavior show unambiguously that the compounds which result from the last-rnentioned type of nucleophilic reagent and cotarnine possess the cyclic form. " Examples of these are cotar-nine anil (20a), cotarnine oxime (20b), cotarnine phenylhydra-zone (20c), anhydrocotarnine carbamide (20d), hydrocotarnyl-acetic acid (20e), anhydrocotarnine acetone (20f), and also the compound (21) obtained from two molecules of cotarnine and one molecule of acetone by the elimination of two molecules of water. The cyclic form had ben demonstrated earlier for anhydrocotarnine-nitromethane (20g) and anhydrocotarnine-acetophenone (20h). ... 

A general process for the preparation of pyrimidines from diacetylene and carbamide derivatives RC(X)NH2 (X = NH, O, S R = Ph, OH, NH2) with fixation and subsequent cyclization of primary products has been patented (94GEP4308073). 

The formation of the pyrimidine ring is due to the addition of carbamide derivatives to the 1,3-positions of the diacetylene system, and according to Maretina et al. (81UK1252), the primary adducts 35 can be isolated in certain cases. 

Prajmaline bitartrate Secobarbital sodium T rioxsalen Allyl carbamide Meralluride... 

Aliphatic polyamine disulfides—imino-, carbamide-, thiocarbamide-, ethylenediamine------are low-effi-... 

Use of low-temperature molten systems for electrolytic processes related with tantalum and niobium and other rare refractory metals seems to hold a promise for future industrial use, and is currently of great concern to researchers. The electrochemical behavior of tantalum, niobium and titanium in low-temperature carbamide-hilide melts has been investigated by Tumanova et al. [572]. Electrodeposition of tantalum and niobium from room/ambient temperature chloroaluminate molten systems has been studied by Cheek et al. [573],... 

SNCR programs typically employing liquid additive formulations based on urea (carbamide, NH2CONH2), together with stabilizers and modifiers, are particularly useful. The additive is sprayed into the combustion area, after the burner. The use of such additives reduces the NOx level by between 50 and 90% by converting NOx into harmless nitrogen and water. 

Carbamide peroxide—aids in removing earwax by softening and breaking up the wax... 

Another indirect electrochemical heahng method involves the artificial kidney machine, with electrochemical regeneration of the dialysis solution. The common kidney machine is a dialyzer in which blood of the patient (who suffers from kiduey insufficiency) and a dialysis solution are pumped arouud iu two differeut loops, aud carbamide (urea), creatinine, and other metabolites are transferred by dialysis into the dialysis solution. For complete extraction of the metabolites, each hemodialysis session requires almost 200 L of this solution to be pumped through, so hemodialysis cau only be performed in a hospital setting. In machines equipped with electrochemical regeueratiou, the dialysis solutiou is ruu iu a closed loop, iucludiug au electrolyzer in which the carbamide is oxidized to nitrogen and carbon dioxide. The solution volume needed in this loop is rather small, so that portable kidney machines could become a reality. 

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