| 摘要 |
NEW MATERIAL:Fluoran derivatives of formula I (wherein R is CH3, C2H5). EXAMPLE:3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofluoran derivative of formula II. USE:Fluoran derivatives are heat-sensitive color forming components useful as a color forming component for thermal recording materials having excellent fastness to plasticizers, oils, org. solvents, etc. PREPARATION:2mol of a compd. of formula III is reacted with 1mol of a ketone of formula IV (wherein R is as defined above) in the presence of a condensing agent such as sulfuric acid, etc. and a catalyst such as FeCl3, etc. at 30-80 deg.C in the presence or absence of a polar solvent such as acetonitrile for 5-60hr. The reaction product is introduced into ice/water and neutralized. The resulting precipitate is recovered by filtration, dissolved in benzene, washed with an aq. soln. of 2% NaOH, concentrated and recrystallized from an org. solvent such as toluene, etc. to obtain a fluoran derivative in a high purity. |
