| 摘要 |
Triacyl derivatives of cyanuric acid are obtained reacting cyanuric acid with a ketene of the formula <FORM:1106559/C2/1> wherein R1 and R2, which may be the same or different, are hydrogen atoms, phenyl radicals alkyl radicals having 1 to 4 carbon atoms at a temperature of from 10 DEG to 100 DEG C. in an inert temperature of from 10 DEG to 100 DEG C. in an inert reaction medium in which the cyanuric acid is soluble to at least 100 p.p.m. and which will dissolve substantially all of the final triacylated product, and in the presence of a basic catalyst which is either:- (a) An alkali metal or alkaline earth metal salt of a weak acid, the salt having a pKb not greater than 10.5; or (b) A tertiary amine or quaternary ammonium compound having a pKb of not greater than 8.5, the basic catalyst and the cyanuric acid being only sufficiently soluble in the said inert reaction medium to permit the reaction to proceed, and then isolating the desired acyl derivative from the reaction medium. The preferred catalyst is sodium acetate. Other specified catalysts include potassium acetate, tri-sodium cyanurate, di-sodium cyanurate, sodium carbonate, sodium benzoate, calcium acetate, triethylamine, trimethylamine, tetramethylammonium acetate and tetraethylammonium acetate. Specified inert reaction media include acetone, ethyl acetate, tetrahydrofuran, dioxane, methyl ethyl ketone, ethylene glycol dialkyl ether or an acetyl ester of ethylene glycol. Triacetyl cyanurate is obtained by treating cyanuric acid with ketene in the presence of various catalysts. Tri(diphenylacetyl)cyanurate is prepared by reacting cyanuric acid with diphenyl ketene in the presence of sodium acetate. |
