4-Toluenesulfonyl chloride → 9-Fluoro-6-(p-toluenesulfonyloxy)benzo[g]isoquinoline-5,10-dione

Participants

Reaction Steps

The 1:1 mixture of 9-fluoro-6-hydroxybenzo[g]isoquinoline-5,10-dione and 9-chloro-6-hydroxybenzo[g]isoquinoline-5,10-dione, of Preparative Example 9a, (0.060 g) is dissolved in dry pyridine (2 mL) and p-toluenesulfonyl chloride (0.095 g) is added. After stirring at room temperature for one hour, triethylamine (0.25 mL) is added and stirring is continued for one additional hour. The reaction mixture is concentrated almost to dryness and partitioned between 1N HCl (4 mL)-20% ammonium sulfate (6 mL) and ethyl acetate (10 mL). The aqueous phase is separated, extracted with ethyl acetate (3×5 mL) and discarded. The combined organic solutions are dried over anhydrous sodium sulphate and concentrated to dryness to give an approximately 1:1 mixture (0.095 g) of 9-fluoro-6-(p-toluenesulfonyloxy)benzo[g]isoquinoline-5,10-dione and 9-chloro-6-(p-toluenesulfonyloxy) benzo[g]isoquinoline-5,10-dione which is used without further purification for the next step.

Provenance & Evidence