I have tried the 2-substituted 1,3-benzodioxole derivative of daphnetin (7,8-dihydroxycoumarin) by literature methods of 2-substituted 1,3-benzodioxoles of catechol and aromatic acids. I have tried the reaction with 1:1, 1:1.2 stochiometry with polyphosphoric acid (excess). Another reaction with PTSA. Other with PTSA Cu adduct. I tried with conventional heating in water bath. Does it mean the OH groups have been deactivated by presence of coumarin ring when I worked up the reaction? Though no product on TLC with water, I found the solid obtained has different nature (gray colored product with different MP) whereeas daphentin is yellowish crystalline. I am assuming that my substituted product should be nonpolar and should run ahead of daphnetin. Is my assumption right? Finally, I found that benzoic acid is running ahead of daphnetin in TLC . Why is daphnetin more polar than benzoic acid? I am stuck in s simple reaction. Do you have any solutions??