AbstractAn intramolecular Ullmann reaction of bromophenethylisoquinoline (X) was investigated in order to obtain the homocularine type compound (V), which could be one of the potential alkaloids belonging to 1‐phenethylisoquinoline series. Methylation of the phenolic 8‐hydroxyisoquinoline (XVIII), one of the position isomers which was separated by silica gel chromatography from a mixture of 6‐hydroxy‐ (XVII) and 8‐hydroxyisoquinoline (XVIII) prepared as usual, gave the starting material (X), which was cyclized by the Ullmann reaction in the presence of cupric oxide. The structure of our objective homocularine (V) was assigned from spec