The Alkaline Hydrolysis of Azo Disperse Dyes (IV) -Mechanism of the Alkaline Hydrolysis of Heterocyclic Azo Dyes-

아조계 분산염료의 알칼리 가수분해(IV)-헤테로환 아조염료의 알칼리 가수분해 반응 메카니즘-

Alkaline hydrolysis reaction of heterocyclic auto disperse dyes was discussed and reaction mechanism was proposed. The FT-IR spectra of auto dye derived from dichlorobenzothiazole and its hydrolysis product were almost the same suggesting the dye was stable for alkali. However, auto dyes derived from nitrothiazole and dinitrothiophene were very rapidly hydrolyzed by alkali with large hypsochromic and hypochromic shifts. Their hydrolyzed products were water-soluble and different from those of the original dyes. Molecular weights of the hydrolyzed products were about half of those of the original dyes. Their hydrolysis mechanism may be explained by the rapid nucleophilic attack of OH- on the carbon adjacent to auto group, electron density of which decreased due to the strong electron-withdrawing group such as vitro group.