p-Toluenesulfonic acid → HCID 21506067, compound

Participants

Reaction Steps

To a suspension of 3-amino-4-phenoxy-5-sulphamyl-benzoic acid (1.54 g) in acetic acid (30 ml), piperonal (0.75 g) was added. After the addition of platinum oxide (25 mg) and a catalytic amount of p-toluenesulphonic acid, the reaction mixture was hydrogenated at room temperature and 1.1 atmospheres hydrogen pressure until the hydrogen uptake had become negligible. Then the reaction mixture was filtered by suction. The filter cake was suspended in water (100 ml), and the pH was adjusted to 8.5 by addition of lithium hydroxide. After the catalyst had been removed from the resulting solution, the 3-(3,4-methylenedioxybenzylamino)-4-phenoxy-5-sulphamyl-benzoic acid was precipitated from the filtrate by addition of 4N hydrochloric acid until the pH was 3. After recrystallization from methanol, the melting point was 229°-230°C.

Provenance & Evidence