NEW MATERIAL:Fluoran derivatives of formulaIwherein R is a 3W5C alkyl; X is halogen.
USE: Color couplers which are applicable to heat-sensitive recording paper, pressure-sensitive recording paper, electrothermorecording paper, etc. Pure black color can be developed by closely contacting these fluoran derivative with an electron-accepting substance such as bisphenol A or an org. acid. The formed recording sheet is highly sensitive to heat, and little suffers fogging.
PREPARATION: 4-Butyl-3'-hydroxydiphenylamine of formula II is condensed with phthalimide of formula III in the presence of an acid such as boric acid. The condensate is hydrolyzed with an alkali to obtain 4-butyl-anilino-2-hydroxy-2'- carboxybenzophenone of formula IV which is then reacted with a 4-methoxy-2'- halodiphenylamine of formula V to obtain the desired compd.
TAKIGUCHI YASUYUKI
IWATA SUSUMU
