Knorr Pyrrole Synthesis

L. Knorr, Ber. 17, 1635 (1884); Ann. 236, 290 (1886); L. Knorr, H. Lange, Ber. 35, 2998 (1902).

Formation of pyrrole derivatives by condensation of α-amino ketones as such or generated in situ from isonitrosoketones with carbonyl compounds containing active α-methylene groups:

A. H. Corwin, Heterocyclic Compounds 1, 287 (1950); H. Fischer, Org. Syn. coll. vol. III, 573 (1955); S. Hauptmann, M. Martin, Z. Chem. 8, 333 (1968); A. J. Castro et al., J. Org. Chem. 35, 2815 (1970); Y. Tamura et al., Chem. & Ind. (London) 1971, 767; H. Rapoport, J. Harbuck, J. Org. Chem. 36, 853 (1971); E. Fabiano, B. T. Golding, J. Chem. Soc. Perkin Trans. I 1991, 3371; A. Alberola et al., Tetrahedron 55, 6555 (1999). Synthetic applications: J. A. Bastian, T. D. Lash, ibid. 54, 6299 (1998); P. E. Harrington, M. A. Tius, Org. Lett. 1, 649 (1999); L. Cheng, D. A. Lightner, Synthesis 1999, 46. Cf. Hantzsch Pyrrole Synthesis; Paal-Knorr Pyrrole Synthesis.