Sulfuric Acid → 9-Chloro-6-fluorobenzo[g]isoquinoline-5,10-dione

Participants

Reaction Conditions

Reaction Steps

Fuming sulfuric acid (30% SO3 ; 0.31 mL) is added to 4-(5-chloro-2-fluorobenzyl)nicotinic acid of Preparative Example 12. The dark mixture is heated quickly to 130° C. for 10 min in a flask fitted with a cotton filled drying tube. After cooling to room temperature, the reaction mixture is quenched with ice (3 g) and extracted with methylene chloride (4×7 mL). The combined extracts are dried with Na2SO4 and the solvent is removed by roto-evaporation to yield 9-chloro-6-fluorobenzo[g]isoquinoline-5,10-dione as a yellow solid (0.045 g; 82% yield).

Provenance & Evidence