Tetrafluoroboric acid → 4-Hydroxy-1,8-naphthalenedicarboxylic anhydride

Participants

Reaction Steps

To a solution of 1.0 g (4.7 mmol) of 4-amino-1,8-naphthalic anhydride in 5 mL concentrated sulfuric acid at 0° C. to 5° C. was added 1.0 g (14.5 mmol) of sodium nitrite, and then 0.5 mL of water. The reaction was stirred for 30 minutes at 0° C. to 5° C., followed by addition of 5 mL (38 mmol) of 48% aqueous fluoroboric acid, with stirring for 30 minutes. The mixture was poured into ice water. The precipitate was isolated, suspended in a solution of 10 mL concentrated sulfuric acid in 50 mL water, refluxed in 3 hours, and again poured onto ice. The precipitate was isolated, washed with water, and dried to yield 620 mg of the title compound.

Provenance & Evidence