Carbonyl diamide

Urea (carbamide, carbonyl diamide, CAS no 57-13-6, molecular weight 60.08) is a white, crystalline, and quite inexpensive powder. The substance is hygroscopic, freely soluble in water, slightly soluble in alcohol, and practically insoluble in ether.15 It is readily incorporated in topical formulations by virtue of its solubility. However, urea in solution hydrolyzes slowly to ammonia and carbon dioxide.15 In one patent it is claimed that lactic acid retards the decomposition of urea.16 Unstable preparations may need to be stored in a refrigerator.15... 

SYNS CARBAiMIDE CARBAMIDE RESIN CARBAAfiMIDIC ACID CARBONYL DIAMIDE CARBONYLDIAMINE ISOUREA NCI-C02119 PRESPERSION, 75 UREA PSEUDOUREA SUPERCEL 3000 UREAPHIL UREOPHIL UREVERT VARIOFORM II... 

Synonyms cas 57-13-6 carbamide carbamide resin carbamimidic acid carbonyl diamide ... 

Carbonylbis 1,3-isobenzofurandione 4,4 -Carbonylbis (phthalic anhydride). See 3,3, 4,4-Benzophenone tetracarboxylic dianhydride Carbonyl diamide Carbonyidiamine. See Urea 1,3-Carbonyi dioxypropane. See Propylene carbonate 4,4 -Carbonyidiphtnaiic acid anhydride 4,4 -Carbonyldiphthalk anhydride. See 3,3, 4,4-Benzophenone tetracarboxylic dianhydride Carborundeum Carborundum. See Silicon carbide Carbothialdine. See3,5-Dimethyl tetrahydro-2-H,1,3,5-thiadiazone-2-thione Carboxyaniline 2-Carboxyaniline o-Carboxyaniline. SeeAnthranilic acid Carboxybenzene. See Benzoic acid Carboxyethane. See Propionic acid... 

Synonyms Carbamide Carbamide resin Carbamidic acid Carbamimidic acid Carbonyl diamide CarbonyIdiamine Isourea Pseudourea Classification Organic compd. 

Carbonyl chloride. See Phosgene Carbonyl chloride, thio-. See Thiophosgene Carbonyl diamide Carbonyidiamine. See Urea Carbonyl dichloride. See Phosgene Carbonyidihydrazine. See Carbohydrazide... 

Urea, also named carbamide or carbonyl-diamide, was first synthesized by Wohler in 1828 from ammonia and cyanic acid. It is a colorless crystalline material, soluble in water and in alcohol but not in ether. Urea contains 46 percent nitrogen, the most of any ordinarily solid fertilizer material. Ammonium nitrate contains 34 percent nitrogen. Urea is not... 

Barbituric acid can be considered as a cyclized malonic acid diamide (malonyl-urea). It is therefore a cyclic diketone that may be classified, in the sense of the compounds discussed in Section 12.6, as a coupling component with a methylene group activated by two carbonyl groups in the a- and a -positions. The reaction with arenediazonium salts was studied by Nesynov and Besprozvannaya (1971). These authors obtained coupling products (in good yield) that they considered to be arylhydrazones. Coupling with 4-(phenylazo)benzenediazonium chloride was studied by Chandra and Thosh (1991). The lH NMR spectra of these compounds are consistent with the arylhydrazone structure 12.68. 

The Leuckart-Wallach reaction is the oldest method of reductive amination of carbonyl compounds. It makes use of formamide, formic acid or ammonium formate at high temperature. The final product is a formamide derivative, which can be converted to an amine by reduction or hydrolysis. The method has been applied to the preparation of 1,2-diamines with a norbornane framework, which are interesting rigid analogues of 1,2-diaminocyclohexanes. As a matter of fact, starting from N-acetyl-2-oxo-l-norbornylamine 222, the diamide 223 was obtained with excellent diastereoselectivity and then converted to the M-methyl-N -ethyl derivative 224 by reduction with borane [ 104] (Scheme 34). On the other hand, when the reac-... 

The first chiral phases introduced for gas chromatography were either amino acid esters, dipeptide, diamide or carbonyl-bis(amino acid ester) phases [721,724,756-758]. In general, these phases exhitdted poor thermal stability and are infrequently used today. Real interest and progress in chiral separations resulted from the preparation of diamide phases grafted onto a polysiloxane backbone. These phases were thermally stable and could be used to prepare efficient open tubular columns [734,756,758-762]. These phases are prepared from commercially available poly(cyano-propylmethyldimethylsiloxanes) or poly (cyanopropylmethylphenyl-... 

CDI and the other A /V -carbonylbisazoles of sufficiently high reactivity react with alcohols ROH to produce diesters of carbonic acid RO-CO-OR, and with amines R R2NH to give diamides of carbonic acid (ureas) R N-CO-NR 2. By use of corresponding bifunctional partners, heterocyclic systems are accessible through insertion of the carbonyl group between two heteroatoms (see Chapter 7). 

Asymmetric lactonization.1 The diamide 3, prepared from (R)-l and 2, on treatment with TFA is converted into the 8-lactone 4 in 98% de by a highly diastereoselective reaction with the pro-S-carbonyl group of 3. 

However, similar cyclization of the related diamide 6 results in the -/-lactone 7, formed with moderate diastereoselectivity with the pro-R carbonyl group. The unexpected asymmetric bias is ascribed to the highly strained diamide ring of 6. 

Four-component condensation (4CC) of carboxylic acids, C-isocyanides, amines, and carbonyl compounds to afford diamides. Cf. Passerini reaction. 

First reported in 1959 [54], this four-component reaction involves a carbonyl compound, an amine, an isocyanide and a carboxylic acid to form a diamide (Scheme 24). 

Dithiocarbamates, in Ru and Os half-sandwiches, 6, 493 Dithiocarbenes, Pt complexes, 8, 439 Dithiocarboxy ligands, in molybdenum carbonyls, 5, 447 Dithiolate-bridged compounds in dinuclear iron compounds with Fe-Fe bonds, 6, 238 as iron-only hydrogenase biomimetic models, 6, 239 Dithiolate diamides, with Zr(IV), 4, 784 Dithiolene—uranium complexes, synthesis and characterization, 4, 212 Ditopic receptors, characteristics, 12, 489 Ditungsten complexes, associated reactions, 5, 748 Divinyllead diacetates... 

One of the main principles for chiral separation used in modern capillary GC is the bonding of the optically active compounds via hydrogen bridges to a stationary-phase material. Feibush and Gil-Av [8] suggested a rapid and reversible formation of association complexes between carbonyl and amide functions of selector and selectand. The formation of diastereomeric associates yields complexes of different stability, depending on the relative configuration. The introduction of dipeptide and diamide phases leads... 

Thus it appears that the starting methyl ester gg undergoes base-catalyzed cyclization to give the intermediate 12, which is opened by hydroxide attack at phosphorus to give lg. The desired diamide 9, formed either by direct hydrolysis of c or by opening of the intermediate 2 at the carbonyl carbon, loses ammonia with assistance from the free carboxylate to give li-... 

There have been many reported chiral stationary phases for use in both packed and capillary gas chromatography. Most of these phases are of the carbonyl-bis-L-valine isopropyl ester, diamide, and peptide phase types. The most common phase is Chirasil-Val from Alltech Applied Science Laboratories (State College, PA). This phase is ideal for the separation of a variety of enantiomers including amino acids, sugars, amines, and peptides. The phase is composed of L-valine-tert-butylamide linked through a car-oxamide group to a polysiloxane backbone every seven dimethylsiloxane units apart. 

Typical lubricants are fatty alcohols C]2-C22, fatty acids C14-Ci8, their esters with fatty alcohols, glycerol or pentaerythritol, amides (2) or diamides (3) and metallic soaps (see Heat stabilizers ), acids C28-C31 from montan wax and their esters, diesters of phthalic acid (4b), paraffin wax C2o-C70, PE waxes Ci25-C70o or their oxidized (polar) grades containing hydroxyl and carbonyl groups. 

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