A process for producing fluorene compounds.

摘要

Chromogenic fluorenespirolactone compounds of formula II are synthesised by reacting a corresponding phthalide or aza-phthalide of formula I in the presence of an aluminium halide, a carboxyl compound and a compound having at least one hydroxyl group, to effect an intramolecular ring closing condensation reaction. The inclusion of the hydroxyl compound shortens the reaction time and reduces the extent of the undesired dealkylation side reaction. <CHEM> a