| 摘要 |
The invention teaches an improved process for the manufacture of useful fluoran dyes of the structure according to formula 1 (1) comprising condensing in an alkanesulfonic acid or an arenesulfonic acid to acid according to formula 2 (2) HO with an aminodiphenylamine of formula 3 o. R (3) R1V R2 wherein R, R1 and R2 are each independently selected from alkyl (Ci-C8), aryl or aralkyl; wherein aromatic ring in aryl or aralkyl may be unsubstituted or substituted with alkyl (Ci-Cg), alkoxy (Ci-Cs), or halogen; wherein Ri-N-R2 may form pyrrolidinyl, piperidinyl and morpholinyl ring moieties; wherein R3, R4, R5 and R6 are each independently selected from hydrogen, alkyl, cycloalkyl, alkoxy, halogen, aryl or aralkyl; wherein the aromatic ring in aryl or aralkyl may be unsubstituted or unsubstituted with alkyl, alkoxy or halogen; said alkyl or alkoxy moieties being from one to eight carbons; or R3 and R4 or R4 and R5, or R5 and R6, may form alicyclic or aromatic ring structures. Higher yields are achievable as compared with conventional processes. |
