Cesium carbonate → 7-bromo-2-(4-fluorobenzyl)-2H-3,5-diazaisoquinolin-1-one

The alkylation of 7-bromo-1-hydroxy-3,5-diazaisoquinoline (1.00 g, 4.46 mmol) using methyl 4-fluoro-benzyl bromide (1.27 g, 6.69 mmol) and cesium carbonate (2.18 g, 6.69 mmol) in dimethyl-formamide is carried out as previously described in Example 1, Step (1). Purification on a silica gel column eluted with hexanes/ethyl acetate 3:1, followed by trituration with hexanes/ethyl acetate 4:1 will afford the desired product. Step (2): 2-(4-fluorobenzyl)-7-3-phenylprop-1-ynyl-2H-3,5-diazaisoquinolin-1-one