Water → 4,6-Dimethoxyisatoic anhydride

Participants

Reaction Steps

To a cooled (0° C.) brown solution of 4,6-dimethoxy anthranilic acid (76.0 g, 0.385 mol), prepared as in Example 2, in tetrahydrofuran (1.3 L) was added triphosgene (40.0 g, 0.135 mol) in portions over a 20 min period. After 30 min, the reaction was warmed to room temperature and stirred for an additional 1.5 h. The reaction mixture was poured into an Erlenmeyer flask containing water and cooled to 0° C. with an ice bath. Additional water was added to facilitate the stirring of the thick solid formed. After stirring for 30 min, the reaction mixture was filtered to give a beige solid. The solid was washed with water, air-dried, and then dried under high vacuum to give 79.2 g (92%) of the isatoic anhydride.

Provenance & Evidence