| 摘要 |
The invention comprises esters of cyanic acid having the formula <FORM:1007790/C2/1> in which R represents an alkyl radical containing an electron-attracting substituent, an aryl radical, a substituted aryl radical which does not contain sterically hindered substituents in both ortho positions, or a heterocyclic radical and x is 1-6. They may be prepared by reacting a compound of formula <FORM:1007790/C2/2> with a cyanogen halide at a temperature from -30 DEG to +65 DEG C. in a solvent in the presence of less than one equivalent of a base, based on the cyanogen halide. R may be, for example, a phenyl radical substituted by an alkyl group or by one or more dialkylamino, acylamino, arylamino, halogeno, nitro, sulphonic acid, sulphonic acid ester, sulphonamide, free or esterified, carboxylic, carboxylic amide, alkoxy, phenoxy, acyloxy, acyl, aldehyde, sulphono, thiocyanate isothiocyanate, alkylmercapto, arylmercapto, acylmercapto or cyano radicals, substituted or unsubstituted a - or b -naphthyl, bisnaphthyl, phenanthryl or anthraquinyl radicals, quinonyl, pyrazolyl, 3-pyridyl, benztriazolyl, carbazolyl, benzthiazolyl or benzimidazolyl radicals; or an alkyl group substituted by a halogen atom, an acyl, carboxylic, esterified carboxylic, sulphonic acid, sulphonic acid ester, nitro, cyano or acetylenic radical. Specification 877,840 are referred to. |
