| 摘要 |
NEW MATERIAL:A salicylic acid derivative of formula I (one of R1-R4 is formula II and at least one from the others is alkyl, cycloalkyl, aryl and the remainders are H; X is H, divalent or polyvalent metal; R5 is H, methyl; when X is H, n is 1; when X is a polyvalent metal, it represents its valency). EXAMPLE:3-Vinyl-5-isopropylsalicylic acid. USE:It is used as a coupler for leuco dyes in pressure-sensitive or heat-sensitive recording paper. It has high light emission and resistance to water, and is used very effectively as a recording material with high concentration color development. PREPARATION:For example, 2-ethylphenol is allowed to react with carbon dioxide in the presence of an anhydrous alkali carbonate under elevated temperature and pressure, the product is converted into methyl ester, substituted with bromine, subjected to dehydrobromination and reaction with isopropyl chloride, and finally the product is hydrolyzed to give the compound of formula I. |
