35219-19-3Relevant academic research and scientific papers
Synthesis of imidazo[1,2-α]pyridines from unactivated 2-alkyl-4,5-dihydroimidazoles through conjugate N-addition
Jones, Raymond C.F.,Dimopoulos, Paschalis,Coles, Simon C.,Light, Mark E.,Hursthouse, Michael B.
, p. 2331 - 2342 (2000)
2-Alkyl-4,5-dihydroimidazoles undergo annulation with α,β-unsaturated aldehydes and ketones via conjugate addition of the N-1 nitrogen atom and subsequent enamine-aldol condensation of C(α) to form imidazo[1,2-α]pyridines having reversed regiochemistry of annulation from that observed with a dihydroimidazole carrying an activating group at C(α); annulation with β-ketoesters also affords imidazo[1,2-α]pyridines, but now with the same regiochemistry as found with a C(α)-activated dihydroimidazole and necessitating a revision of earlier reported structures. Dialkyl acetylenedicarboxylates undergo conjugate N-addition but act as 1,2- rather than 1,3-bis-electrophiles to form pyrrolo[1,2-α]imidazoles. The Royal Society of Chemistry 2000.
Synthesis and evaluation of dihydroimidazolo and dihydrooxazolo ring-fused 2-pyridones-targeting pilus biogenesis in uropathogenic bacteria
Pemberton, Nils,Pinkner, Jerome S.,Edvinsson, Sofie,Hultgren, Scott J.,Almqvist, Fredrik
, p. 9368 - 9376 (2008/12/22)
Dihydrothiazolo ring-fused 2-pyridones have previously been shown to inhibit pilus assembly in uropathogenic Escherichia coli. Methods have now been developed to synthesize both dihydroimidazolo and dihydrooxazolo ring-fused 2-pyridones. To obtain the nitrogen analogs, Cbz-protected imidazolines were reacted with an acyl-Meldrum's acid derivative under acidic conditions. To prepare the oxygen analogs, a one-pot procedure was developed that allowed synthesis of dihydrooxazolo ring-fused 2-pyridones starting from acylated serine derivatives. After hydrolysis to their corresponding carboxylic acids and lithium carboxylates, biological evaluation revealed that the sulfur could be replaced by an oxygen atom and still maintains the ability to inhibit pilus assembly in uropathogenic E. coli. However, introducing a secondary amine instead of oxygen resulted in a substantial decrease in biological activity.
