6-Aminohexanoic Acid → 1,3-Dihydro-1,3-dioxo-2H-isoindole-2-hexanoic acid

Participants

Reaction Steps

6-amino hexanoic acid (39a) (13.1 g, 100 mmol) and phthalic anhydride (40) (14.8 g, 100 mmol) were mixed in toluene (150 mL). To the suspension was added triethyl amine (13 mL). The suspension was refluxed using Dean-stark for 16 h. When collection of water ceased, the reaction was cooled and evaporated to dryness. The residue was suspended in water and conc. hydrochloric acid (1.5 mL) was added. The suspension was stirred for 30 mins and filtered. The precipitate was washed with water and dried over sodium sulfate to afford compound 41a (24.5 g, 93%) which was used as such for the next step.

Provenance & Evidence