反应详情

A solution of 2-(carboxymethyl)indane-2-carboxylic acid from Step C (1.10 g, 4.99 mmol) in acetyl chloride (18 mL) was heated at reflux for 18 h, then concentrated in vacuo. The residue was recrystallized from toluene to give 1′,3′-dihydrospiro[furan-3,2′-indene]-2,5(4H)-dione as an ivory solid. This solid was dissolved in CH2Cl2 (25 mL) and NH3 (g) was bubbled into the mixture for 20 min. After a further 30 min, the solvent was evaporated under reduced pressure. The resulting solid was dried under high vacuum for 1 h, then resuspended in acetyl chloride (20 mL) and heated to reflux for 18 h. The solvent was removed in vacuo and the crude solid was recrystallized from EtOH:Et2O to afford the title compound. MS: m/z=202 (M+1).

1. temperatureat reflux for 18 h
2. concentrationconcentrated in vacuo
3. customThe residue was recrystallized from toluene