2-[(2-methyl-1,3-dioxolan-2-yl)methyl]isoindole-1,3-dione

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of phthalimidoacetone ethylene ketal (2.47 g, 10 mmole) in 10 mlof diethylene glycol is heated on a steambath. To this hot solution bromine(1.6 g, 10 mmole) is added dropwise under nitrogen. The reaction mixture iscooled to room temperature and is quenched in 20 ml hexane. To this mixtureis added solid sodium carbonate followed by chloroform and ice water. The organic layer is separated and the aqueous layer is extracted 3 times withchloroform. The chloroform extracts are washed with water, dried over anhydrous sodium sulfate, and evaporated in vacuo. The residue is crystallized from ethyl acetate/hexane to afford 2 g (55%) of (3-phthalimidoacetonyl)bromide, ethylene ketal as white prisms of melting point 139°-141° C. An analytical sample has a melting point of 140°-141° C. iscooled to room temperature is quenched in 20 ml hexane To this mixtureis added solid sodium carbonate The organic layer is separated the aqueous layer is extracted 3 times withchloroform The chloroform extracts are washed with water dried over anhydrous sodium sulfate evaporated in vacuo The residue is crystallized from ethyl acetate/hexane