To 0.504 g (2.70 mmol) of 7-aminonaphthalene-2-carboxylic acid (106; prepared according to the procedure in Harrison, H. A. and Royle, F. A. J. Chem. Soc., 1926, 84) was added 10 mL of dioxane, 5 mL of 10% sodium carbonate, and 35 mL of water. To this clear solution was added 0.786 g (2.97 mmol) of 9-fluorenylmethyl chloroformate, portionwise, over 15 minutes. After 3 hours, the reaction was acidified with 1N HCl and the resulting white precipitate was collected by vacuum filtration. This solid was suspended in diethyl ether and stirred to give a fine precipitate that was collected by vacuum filtration. This provided 0.948 g of compound 107.
