Regioselective friedel-crafts acylation with unsymmetrically substituted furandicarboxylic acid anhydride and furan acid chloride: Syntheses of 4-substituted 3-arylcarbonyl-2-phenylfuran and 3-substituted 4-arylcarbonyl-2-phenylfuran

Friedel-Crafts acylation of aromatic compounds with 2-phenylfuran-3,4-dicarboxylic acid anhydride (4) and 3-methoxycarbonyl-2-phenylfuran-4-carboxylic acid chloride (6) was studied. The reaction with 4, unsymmetrically substituted cyclic anhydrides, afforded 2-phenyl-3-arylcarbonylfuran-4-carboxylic acids (7) in moderate to good yields. Possible mechanism for such regioselective ring opening was also proposed. No interchanged isomeric product was noted for acylation of aromatic compounds with ester acid chloride (6). The synthesis of the precursor of 6, 3 -methoxycarbonyl-2-phenylfuran-4-carboxylic acid (5), was achieved by regioselective hydrolysis from dimethyl 2-phenylfuran-3,4-dicarboxylate (2).Chemistry, OrganicSCI(E)1ARTICLE2265-2775