Biuret alkyl

The common method of preparation of 6-alkyl-2,4-dioxotetrahydro-triazines is the cyclization of acyl-biurets by aqueous hydroxide. Formyl biuret which should by analogy 3deld 5-azauracil had not been known until recently. Its transient formation can be expected during further synthesis of 5-azauracil. Piskala and GuP achieved... 

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-... 

In the melt-dispersion process (95), an NCO-terminated prepolymer is prepared next from a polyester or polyether diol, a diisocyanate, and a glycol containing a potential ionic group. The NCO/OH is between 1.2 and 1.8. Then, the prepolymer is terminated with urea to form biurets, which are further alkylated to give an ionomer as shown in Fig. 17. The bis-biuret can be considered to be somewhat hydrophilic to be methylolated with formaldehyde. Upon dilution with water, a stable dispersion is formed. 

Biuret acyl-, 194 alkyl-, 197 formyl-, 194, 195 preparation of, 194 reactions of, 195, 200 Bromine titration, as method to study tautomerism, 1... 

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