Synthesis ofN,N′-Linked Bisazaheterocycles

Abstract

Bisazaheterocycles are excellent precursors of N-centered free radicals with immense pharmacological importance. The synthesis of various N,N¢-linked bisazaheterocycles and their importance is reviewed for the first time.

Intramolecular Cyclization with Nitrenium Ions Generated by Treatment of N-Acylaminophthalimides with Hypervalent Iodine Compounds: Formation of Lactams and Spiro-Fused Lactams

“…These N-amino compounds should be useful starting compounds for the synthesis of N,N′-linked bisazaheterocycles. 11 The oxidative rearrangement of N-amino-2indolinone with lead tetraacetate and t-BuOCl gave 3(2H)-cinnoline. 12 N-Amino-2-indolinone also can be converted to the corresponding amino-nitrene by lead tetraacetate oxidation.…”

1,1′-Bi-1H-benzimidazole-2,2′-dicarbaldehyde

“…Biazoles connected by N-N bonds are often viewed as weakly bound dimers which readily homolyse to two radicals (Zimmermann et al, 1961). While this is the case for biazoles with multiple aromatic substitutents, there are now numerous examples of N-N-linked biazoles with remarkable stability and utility (Reddy et al, 2002). Surprisingly few N-N-linked biimidazoles have been isolated, a trend that is due to their circuitous synthetic access (de Mendoza et al, 1981).…”

Water-Accelerated Synthesis of Novel Bis-2,3-dihydroquinazolin-4(1H)-one Derivatives

“…Furthermore, the study of bis-heterocyclic systems has attracted interest, owing to their potential biological activities. 6 To the best of our knowledge, there are no reports on the synthesis of bis-dihydroquinazolinone compounds 2 and 3 in the literature (Figure 1).…”

“…Calcd for C 17 H 17 N 3 O 3 : C, 65. 6;H,5.5;N,13.5. Found: C,65.5;H,5.5;N,13.2. 3-Ethyl-2,3-dihydro-2-(4-hydroxyphenyl)quinazolin-4(1H)-one (1o) White solid; mp 180-182 °C.…”