A stirred solution of Pd(OAc)2 (16 mg, 0.07 mmol), PPh3 (61 mg, 0.23 mmol), Et3N (0.58 mL, 4.2 mmol) and (Z)-ethyl 4-(2-iodo-4,5-dimethoxybenzamido)but-2-enoate (860 mg, 2.1 mmol) in dry CH3CN (20 mL) was heated at 70° C. overnight under an argon atmosphere. The reaction was allowed to cool to room temperature and then concentrated under reduced pressure. The residue was purified by flash chromatography using DCM/MeOH 100:1 (v:v) as eluent to give (Z)-ethyl 2-(6,7-dimethoxy-1-oxo-2,3-dihydroisoquinolin-4(1H)-ylidene)acetate (510 mg, 83%). LC-MS (ES-API); rt 7.56 min; m/z calculated for C15H17NO5 [M+H]+ 292.1, found 292.1.
