procedure for deacylering of relations involving two aromatic nuclei

摘要

Diacylation of compounds of general formula IMAGE with X : O, S, IMAGE or -CH2- R1, R2, R3 and R4, which are identical or different: H or an alkyl radical containing from 1 to 4 carbon atoms, by bringing the compound (I) into contact with HF, BF3 and at least 2 moles of an acylating agent per mole of (I) at a temperature of between -40 DEG C and 0 DEG C.