1,3-Dioxo-1H-benzo[de]isoquinoline-2(3H)-acetic acid sodium salt

Alrestatin,BIOMOL

Enzyme inhibitor (aldose reductase).

1,3-Dioxo-1H-benz[de]isoquinoline-2(3H)-acetic acid:
1,8-Naphthalic acid anhydride (110 g, 0.556 mole), glycine (48 g, 0.64 mole) and dimethylformamide (750 ml) are heated and stirred at reflux for 2 hr. The homogeneous dark solution is cooled to about 100°C and 750 ml of hot water is added slowly to the stirred solution. The reaction mixture is cooled and allowed to stand in a refrigerator for 16 hr. The precipitate is collected and recrystallized from ethanol, using decolorizing charcoal, to give the title compound, MP: 271°-272°C.
In practice it is usually used as sodium salt.

Aldose reductase inhibitor