Acetic acid, azido-, ethyl ester → 2-chloro-4H-furo(3,2-b)pyrrole-5-carboxylic acid

Reaktionsgleichung

[Cl:1][C:2]1[O:6][C:5]([CH:7]=O)=[CH:4][CH:3]=1.[Na].C([O:12][C:13](=[O:18])[CH2:14][N:15]=[N+]=[N-])C>C(O)C>[Cl:1][C:2]1[O:6][C:5]2[CH:7]=[C:14]([C:13]([OH:18])=[O:12])[NH:15][C:4]=2[CH:3]=1

Komponenten

Versuchsvorschrift

5-Chloro-furan-2carbaldehyde (Snyder, H. R., Jr.; Seehausen, P. H., J. Heterocycl. Chem., 10: 385-6 (1973)) was annulated according to Procedure H (8 equiv sodium; aldehyde and azido-acetic acid ethyl ester added as ethanol solution (0.9 M of ester); condensation reaction mixture allowed to warm to room temperature, stirred for 1 h, quenched at −40° C., diluted with water, and extracted with ether; acrylate not purified; crude furanopyrrole filtered before concentration).