Dimethyl biuret

Allophanate Methyl allophanate Biuret Dimethyl biuret Tetramethyl biuret L-Ascorbic acid 2-(2H-Benzotriazole-2-yl)-4,6-ditertpentylphenol Decanedioic acid, bis(2,2,6,6-tetramethyl-l-(octyl-oxy)-4-piperidinyl)ester Bis (l,2,2,6,6-pentamethyl-4-pi-peridinyl)-[[3,5-bis(l,l-dimethyl-ethyl)-4-hydroxyphenyl]methyl]butylmalonate Tinuvin 328 Tinuvin 123 Tinuvin 144... 

Final structure determination of the monomethyl derivatives was made possible only on performing straightforward syntheses of the compounds, analogous to syntheses of allantoxaidine. The 1-methyl (19) and 3-methyl (20) derivatives were prepared by cyclization of 1- and 3-methyl biuret,respectively. The 3-methyl derivative was also obtained by cyclization of A ,A -bis(methylcarbamyl)formami-dxne. The 1-methyl derivative was the same as the product obtained by Biltz on methylation of silver salt of allantoxaidine with methyl iodide. The same product is formed primarily during methylation of dioxotriazine with diazomethane. An excess of this agent produces the expected 1,3-dimethyl derivative (21). These results of alkyl-... 

Biuret triisocyanate-adduct of hexamethylene diisocya- Mobay Chem. Co. nate with water Dibutyltin dilaurate Dimethyl 2,5-bis(ethyl-hexanoyl peroxy)hexane Benzoyl peroxide Calcium naphthenate Lead naphthenate Cobalt naphthenate Zinc naphthenate N-benzyl-N,N,dimethylamine Copper chloride Ferric chloride N,N-(Dimethylaminoethyl)-morpholine -Caprolactone Hydorquinone Xylene... 

Another way of producing a low proton activity at the amalgam surface is to add a suitable polar, aprotic compound to the medium. Suitable compounds include urea and its derivatives, amides, lactams, sulfoxides, and sulfones, such as 1,3-dimethylurea, ethyle-neurea, biuret, formamide, A-methyl formamide, acetamide, 5-butyrolactam, dimethyl sulfoxide, di- -butyl sulfoxide, and dimethyl sulfone [41,42]. Dimethylformamide (DMF) or acetonitrile, besides some of the compounds just mentioned, may be used as solvents [43,44]. One function of the added compound is to establish an aprotic reaction layer at the amalgam surface by selective adsorption of the compound on the amalgam another is to solvate the ion pair (consisting of the radical ion and the cation) in a suitable way. 

Biuret trichlorides .7 Dimethylcyananvide (1) reacts with the reagent in methylene chloride to give almost quantitative yields of N,N,N, N -tetramethyl-l,3-dichloro-2-azatrimethinecyanine (2), a biuret trichloride. This is hydrolyzed under mild conditions to N1,N1-dimethyl-N2-(dimethylcarbamoyl)chloroformamidine (3), hydrolyzable under stronger conditions to the biuret derivative (4). 

St.8 "Dimethyl-N -phenyl-N<>.o-to)yl.iso dithibbiuret 12, 810. 8 -Athyl-N -phenyl-N -o.toIyI-iaodithio biuret 12, 810. 

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