| 摘要 |
NEW MATERIAL:The fluoran compd. is represented by formulaI(where R1-2 are each H or lower alkyl; R3 is H or methyl; R4-5 are each H, methyl, ethyl, halogen or nitro; X is H or Cl; n is 1-4). USE:Color former for heat- or pressure-sensitive recording sheet. PREPARATION:2-(4'-Di-substd. amino)-2'-hydroxybenzoyl) benzoic acid obtained by dehydration condensation of m-aminophenol of formula II with phthalic anhydride of formula III is made to react with a diphenylamine deriv. of formula V (where R6 is lower alkyl) in the presence of a dehydrating condensation agent (e.g. sulfuric acid). Then, the reaction product is poured into ice water and the resultant precipitate is filtered and then treated with alkali to produce a crude fluoran compd., which is recrystallized from a proper solvent (e.g. benzene) to obtain compd. of formulaIin colorless or pale-colored crystals. |
