Aniline → 1,3-Dioxo-2-phenylisoindoline-5-carboxylic acid

Participants

Reaction Steps

4-carboxyphthalic anhydride (benzene tricarboxylic acid anhydride) (1.0 g, 0.0052 mol), aniline (0.96 g, 0.0104 mol), and 70–80 mls of glacial acetic acid were added to a 100 ml round-bottom flask equipped with a reflux condenser, heating mantle and stir plate. The system was placed under a N2 atmosphere. A white solid precipitated out of the clear pale yellow solution within 1 minute. The mixture was heated to a gentle reflux. More precipitate formed during the course of the reaction. After 12 hours the mixture was cooled to room temperature and concentrated under vacuum with a rotary evaporator. The crude material was reprecipitated in 1,4-dioxane and IN HCl. The resultant white precipitate was filtered through a Buchner funnel and washed three times with 15 ml of water. The product was dried in air for 24 hours and then in vacuo for 48–72 hours to afford 1.25 g (90%) 109 as a white fluffy solid: mp=257–258° C.; Rf 0.83 (A): Rf 0.76 (B): Rf 0.62 (D): IR (cm−1): 2800–3125 (OH), 3071 (C═CH), 2665 (C—H), 1788 (C═O), 1719 (bs, C═O), 1602 (C═C), 1596 (C═C), 1504 (C═C), 1487 (C═C), 1399 (C—O), 1124 (C—O), 724 (C═CH); MS m/z (rel intensity) 267 (16), 266 (100).

Provenance & Evidence