Process for preparing fluoran derivatives

Claim 1

A process for preparing 3,6-bis-diarylaminofluoran derivatives represented by the following general formula (III): ##STR4## wherein each of Ar 1 , Ar 2 , and Ar 3 independently represents an aryl group, each of R 1 , R 2 , and R 3 independently represents an alkyl group, an alkoxy group, a halogen atom, a nitro group, an alkylamino group, a dialkylamino group or an acylamino group, x and y each represents 0 or an integer of 1 to 3, and z represents 0 or an integer of 1 to 4, which comprises reacting in a single reaction step a 3,6-bis-arylaminofluoran derivative represented by the following general formula (I): ##STR5## wherein Ar 1 , Ar 2 , R 1 , R 2 , R 3 , x, y, and z are the same as defined above, with 2.0 to 10.0 mols based on one mol of the 3,6-bis-arylaminofluoran derivative of the formula (I) of an arylating agent represented by the following general formula (III): Ar.sub.3 --X (II) wherein Ar 3 is the same as defined above, and x represents a halogen atom or a sulfonyloxy group represented by --OSO 2 R 4 (R 4 represents an alkyl group or an aryl group), whereby both of the arylamino groups of the 3,6-bis-arylaminofluoran derivative of the formula (I) are arylated at the same time.