Coumarins and related compounds. Part XIX. Synthesis of 3-phenyl-benzo[h]coumarin

Abstract

3-Phenylbenzo[h]coumarin (14) has been synthesised from 1-methoxy-2-naphthaldehyde (12) and an improved synthesis of 1-hydroxy-2-naphthaldehyde (11) is described. Attempts to synthesise 3-phenyl-3,4-dihydro-benzo[h]coumarin (15) resulted in the formation of 4-substituted 1-naphthols (3) and (4) when 1-naphthol was condensed with 2-phenylacrylonitrile in the presence of zinc chloride, and of the naphthofuranone (9) when ethyl 2-phenylacrylate and anhydrous aluminium chloride were used.