Acetone → 8-methoxycarbonyl-4,4-dimethyl-4H-pyrrolo[2,1-c][1,4]-benzoxazine

Participants

Reaction Steps

The mixture of methyl 4-hydroxy-3-(pyrrol-1-yl)benzoate (4.0 g), acetone (40 ml) and p-toluenesulfonic acid (0.8 g) in toluene (80 ml) was heated under reflux for 15 hours under stirring. The solvent was removed by evaporation and to the residue was added a mixture of ethyl acetate and water. The mixture was adjusted to pH 8 with potassium carbonate and the separated organic layer was washed with brine, dried over magnesium sulfate and evaporated in vacuo. The residue was purified by column chromatography on silica gel eluting with a mixture of toluene and n-hexane (1:1, V/V). The eluted fractions containing the desired product were collected and evaporated in vacuo. The residue was triturated with a mixture of diisopropyl ether and n-hexane to give 8-methoxycarbonyl-4,4-dimethyl-4H-pyrrolo[2,1-c][1,4]-benzoxazine.

Provenance & Evidence