反应详情

A mixture of 4.2 g (20.0 mmol) of ethyl 3-amino -2-benzo[b]furancarboxylate (EP 187487 A1) in 10 mL of N,N-dimethylformamide dimethyl acetal is heated at reflux temperature for 1.5 hours, then cooled to room temperature and concentrated in vacuo. The residue is partitioned between ethyl acetate and water. The organic layer is washed with water, dried over sodium sulfate, passed through a pad of diatomaceous earth and concentrated in vacuo. The solid is collected by filtration to provide 3.90 g (75%) of a white solid, mp 89-90° C.

1. temperatureis heated
2. temperatureat reflux temperature for 1.5 hours
3. concentrationconcentrated in vacuo
4. customThe residue is partitioned between ethyl acetate and water
5. washThe organic layer is washed with water
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated in vacuo
8. filtrationThe solid is collected by filtration