| 摘要 |
NEW MATERIAL:A compound of formulaI(R1 and R2 are lower alkyl). EXAMPLE:2-(4-Acetylphenyl)amino-6-(N-methyl-N-cyclohexyl)aminofluoran. USE:A precursor for dyes in recording materials, e.g. (electro)thermorecording paper, having a high color developing concentration and a low coloring starting temperature and improved color rise with almost no ground coloring. PROCESS:A diphenylamine compound of formula II (R is H or lower alkyl), e.g. 4-methoxy-4'-acetyldiphenylamine, is reacted with a benzophenone compound of formula III, e.g. 2-[2-hydroxy-4-(N-methyl-N-cyclohexyl)aminobenzoyl]benzoic acid, in the presence of a condensing agent, e.g. concentrated sulfuric acid, at 0-80 deg.C. The resultant reaction mixture is then poured in ice water, and toluene and an aqueous solution of NaOH are added and refluxed to collect the aimed compound from the toluene layer. |
