To a stirred solution of 1,2,3,4-tetrahydro-6,7-dimethoxy-1-methylisoquinoline (20.0 g, 0.096 m) in methylene chloride (300 ml) under nitrogen at ambient temperature was added m-nitrophenylacetic acid (17.5 g, 0.096 m) and then portionwise dicyclohexylcarbodiimide (20.7 g, 0.1 m) and the mixture stirred for 3 hours. The precipitated solid was removed by filtration and the filtrate evaporated to an oily residue. This was treated with 100 ml methanol and 50 ml ether and the solid precipitate collected by filtration and washed with methanol and dried to give N-(3-nitrophenylacetyl)- 1,2,3,4-tetrahydro-6,7-dimethoxy-1-methylisoquinoline as a yellow solid, 22.0 g (64% yield), m.p. 120°-121°.
