Synthesis of 7-amino-1,4-dihydro-4-oxo-6-(trifluoromethyl)-1,8-naphthyridines. The use of methylidenemalonate as an activating group and a sulfur assisted cyclization
作者:A. J. Bridges、J. P. Sanchez
DOI:10.1002/jhet.5570270602
日期:1990.9
2,6-Dichloro-3-(trifluoromethyl)pyridine 3 was used to develop a six-step preparation of 7-amino-4-oxo-6-(trifluoromethyl)naphthyridines. The CF3 group deactivated the pyridine ring towards both nucleophiles and electrophiles. A new reagent for pyridone annulation, the aminomethylidenemalonate anion, is described, along with several strategies to manipulate the electron density of substituted pyridines