Synthesis,colour and absorption maxima study of some novel analogues of phthalein dyes

摘要

We reported recently on a programme of research aimed at obtaining unsymmetrieal phthalides,in which some novel analogues of phthalein dyes (5-12) were synthesised by condensation of V-keto acid,2-(2,5-dichlorobenzoyl) benzoic acid (1) with various phenols (4) in the presence of concentrated sulphuric acid,V-keto acids reacted with phenols through their lactol tautomeric form (2) as shown in the Scheme.