Ethyl bromoacetate → Ethyl [(isoquinolin-5-yl)oxy]acetate

In 10 ml of acetonitrile, 1.0 g of 5-hydroxyisoquinoline and 1.52 ml of ethyl bromoacetate were added in the presence of 2.07 ml of DBU and the resultant mixture was refluxed for 8 hr. The reaction mixture was evaporated under reduced pressure and the resultant residue was redissolved in 1N-HCl, washed with ethyl acetate. The aqueous layer was made alkaline with sodium hydrogencarbonate and extracted with ethyl acetate. The extract was washed with saturated sodium chloride aqueous solution and dried over anhydrous sodium sulfate. The dried solution was evaporated under reduced pressure and subjected to a silica gel column chromatography (chloroform) to give 1.46 g of ethyl 5-isoquinolyloxyacetate. The ester was dissolved in 30 ml of ethanol, mixed with 6.5 ml of 1N-NaOH aqueous solution and stirred for 12 hr. The reaction mixture was evaporated under reduced pressure, neutralized by the addition of 1N-HCl and the precipitated crystals were filtered, washed with water and dried to give 0.68 g of the title compound.