The application relates to the field of preparation of
fluorescein probes with specific selectivity, and specifically discloses a preparation method of
fluorescein probes with specific selectivity. The method comprises: (1) mixing 4-nitrophthalic anhydride,
resorcinol,
nitrocyclohexane and
anhydrous cobalt chloride, heating and melting, adding
zinc chloride, reacting, and then adding
hydrochloric acid Reflux, filter and wash, dry; (2) will contain Na 2 S and Na 2 SO 3 The reducing solution is mixed with the product of step (1), reacted, and then glacial
acetic acid is added dropwise until the
precipitation is complete, filtered, washed, and dried; (3) the mixed
solvent containing
methanol and
triethylamine is mixed with the product of step (2) Mix, add CS dropwise 2 , to react, then add
copper chloride aqueous solution dropwise, continue the reaction after dropping, then adjust the pH value of the
system to 1-2 with
hydrochloric acid, distill under reduced pressure, wash, dry, and purify by
column chromatography. The method greatly improves the conversion rate and yield of 5-
fluorescein isothiocyanate.