Furan ring recyclization in 2‐furfurylthieno[2,3‐b]pyridines: An intramolecular N‐alkylation of pyrrole ring under acid conditions

Synthesis of β‐Lactam‐containing Pyrido[3′,2′:4,5]thieno[3,2‐e][1,4]diazepines

“…As initial compounds, we have chosen 3‐chloroacetylamino‐2‐aroylthieno[2,3‐ b ]pyridines 1a–c , which were first synthesized from corresponding aminoketones by an acylation according to the earlier described procedure (Scheme ). The acylated aminoketones 1 were converted to 1,4‐diazepines 2 by successive treatment with gaseous NH 3 in anhydrous DMF under heating (Scheme ).…”

“…The compounds 1a–c were prepared by treatment of corresponding aminoketones with chloroacetyl chloride using the earlier described procedure .…”

Novel Rearrangement of 3‐Acylaminofuro[2,3‐b]pyridines into 3‐(oxazol‐4‐yl)pyridin‐2‐ones

“…The furfurylfuro[2,3‐ b ]pyridine 1a was treated with ethanolic HCl solution similar to its thieno[2,3‐ b ]pyridine analogs to furnish corresponding pyrrolofuropyridine 5 as a result of acid‐catalyzed furan ring recyclization. However, no pyrrolofuropyridine 5 was obtained from the reaction mixture, and the sole compound isolated was diketone 6 — product of protolytic furan ring opening (Scheme ).…”

“…The compounds 4a , 4b , 4c , 4d , 4e were prepared by reduction of the corresponding ketones 3 with NaBH 4 by using the earlier described procedure .…”

Unusual Oxidative Dimerization in the 3-Aminothieno[2,3-b]pyridine-2-carboxamide Series

“…In continuation of our studies on the synthesis and biological properties of thienopyridines, − we wish now to report the synthesis and structures of new polyheterocyclic ensembles prepared by noncatalyzed oxidative dimerization of 3-aminothieno­[2,3- b ]­pyridine-2-carboxamides.…”