Studer and D. Shi, Chem. The reaction pathway was found to depend on the type of nucleophile used Fig. The results clearly show that the structure of the intermediate 4l is the oxazoline[3,2-a]pyridinium species.
Torres, S. Li, J. Introduction The pharmacodynamic versatility of 4-oxo-4H-chromene moiety has been documented not only in many of its synthetic derivatives but also in several naturally occurring flavones and khellins. Protti and M.
Thus, it is expected that the hydrazide b-nitrogen N-NH2 is more nucleophilic and will react more rapidly with the electron deficient carbon than the second amino group C-NH2. Loratadine and analogues: discovery and preliminary structure-activity relationship of inhibitors of the amino acid transporter B 0 AT2. Norimine, O. Protti and M. Thus, cyclocondensation of 4 with 6-chloroformylchromone 1 in DMF under reflux containing few drops of piperidine afforded the 1,2,3,5-tetrahydro[1,2,4] triazolo[1,5-a]pyridine derivative 7. Engle, D.
Scheme 25 Mn I -Catalysed directed C,3-difluoroallylation.
Daugulis, H. Ackermann, R. Xie and X.
Table 1: Optimization of reaction conditions. After cooling, the reaction mixture was poured onto ice-water, and neutralized with diluted HCl. In contrast, the energy of attacking C8 of 4a by 6I and 6J are much higher
Burton, Org. Ibrahim, M. After cooling, the reaction mixture was poured onto ice-water, and neutralized with diluted HCl. The antimicrobial activities of the prepared compounds showed that polyheterocyclic systems 7, 9 and 15 have good inhibitory effects when compared with the starting material. Anilines with electron donating and withdrawing groups gave good yields of the corresponding pyridones, whereas aromatic heterocyclic amines failed to yield any product 5A-H. Found: C,
Collins, I. Ethyl 8- 6-chlorooxo-4H-chromenyl -7,9-dicyanomethyloxo-1,6-dihydro-4H-pyrido[1,2-b][1,2,4]triazinecarboxylate 10 A mixture of compound 4 mg, 5 mmol and ethyl 2-chlorooxobutanoate mg, 5 mmol , in DMF 30 mL containing few drops of piperidine, was refluxed for 8 h. Drug Des. Ueno, S. Suzuki, Y.