Phthalide-3-carboxylic acid has been decarboxylated in the presence of isoquinoline, 1-chloroisoquinoline and isoquinoline N-oxides to give low yields of compounds resulting from alkylation of the isoquinoline heterocycle at C1 with a phthalidyl group. Attempted Barton decarboxylation-alkylation in the presence of isoquinolinium salts was unsuccessful.