|Prep of Isatoic anhydride from phthalimide||Bookmark|
Org prep and proc Int vol 14 no 3 1982
(from some Indian guys, so take it with a grain of salt)
To a stirred mix phthalimide (147 g 1 mol) crushed ice 400g water 250 mL in 5 L beaker was added slowly by dropping funnel 40 g NaOH in 350 mL water, most of phthalimide dissolved
to the soln at 0 C was added gradually 950 mL 1 M sodium hypochlorite solution over 20 min w/ stirring maintain 4-6 C.
After 15 min acidify conc HCl to pH 6 and stir slurry for 1.5 hr ppt collected and washed with water until washings were colorless and dried at 40-50 C to give 136-140 g isatoic anhydride (85-88%) mp 240-242