Anthranilic Acid → Isatoic Anhydride

Participants

Reaction Steps

An ice-cold solution of triphosgene (3.0 g, 10 mmol, 0.4 eq) in 10 mL of anhydrous THF was added to a mixture or solution of anthranilic acid (or 2-amino-benzoic acid) (25 mmol) in 15 mL of dry THF and cooled slowly. The mixture as then stirred or shaken for 24-48 h at room temperature nd cooled in a refrigerator (0° C. to −10° C.) for 12-24 h. The resulting solid was collected by filtration and washed with cold methyl t-butyl ether (MTBE) and dried to give the isatoic anhydride in 70-98% yield. About 30 isatoic anhydrides were prepared in this manner.

Provenance & Evidence