N-(hydroxymethyl)phthalimide → Phthalamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-methyl-4H-3,1-benzoxazin-2,4-dione (Preparation VIIA) (19.7 g, 111 mmol) in methanesulfonic acid (150 mL) was added N-(hydroxymethyl)phthalimide (20.3 g, 111 mmol). The reaction mixture was heated to 50° C. and stirred for 3 hours. After cooling to room temperature, the reaction mixture was diluted with 2000 mL of Et2O. After stirring for an additional 1 hour, the precipitate was filtered, washed with Et2O and dried affording 30.7 g of crude phthalamide. 1H NMR showed a 3:2 mixture of the 6- and 8-substituted regioisomers respectively. The crude material was used directly in the next reaction where the two regeoisomers were separated.

Provenance & Evidence