50609-73-9Relevant articles and documents
Nitrogen Bridgehead Compounds. Part 6. Ring Transformation. Part 3. Thermal Cyclization of Diethyl 2-(2-Pyridylaminomethylene)-succinates and -glutarates
Vasvari-Debreczy, Lelle,Hermecz, Istvan,Meszaros, Zoltan,Dvortsak, Peter,Toth, Gabor
, p. 227 - 232 (2007/10/02)
The pyridylsuccinates (1) and pyridylglutarates (2), with various substituents on the pyridine ring, were cyclized in Dowtherm A at 250 deg C.The succinates cyclized in two competing reaction routes, giving rise to pyridopyrimidines (route A) and N-pyridylpyrrolinones (route B).The ratio of the two products varied with the nature of the substituent and its position.The N-pyridylpyrrolinones proved to be mixtures of the desmotropes (5) and (6) which were separated.The pyridylglutarates (2) gave only the pyridopyrimidines (4).The 6-substituted pyridopyrimidines underwent a ring-transformation reaction at or above 250 deg C, forming the corresponding 1,8-naphthyridines (8) and (9).