Synthesis of a Spirocyclic Oxetane-Fused Benzimidazole

Molecules. 2015 Jul 30;20(8):13864-74. doi: 10.3390/molecules200813864.

Abstract

A new synthesis of 2-oxa-7-azaspiro[3.5]nonane is described. Spirocyclic oxetanes, including 2-oxa-6-azaspiro[3.3]heptane were converted into o-cycloalkylaminoacetanilides for oxidative cyclizations using Oxone® in formic acid. The expanded spirocyclic oxetane successfully gave the [1,2-a] ring-fused benzimidazole. X-ray crystal structure of the resultant new tetracyclic system, 1',2'-dihydro-4'H-spiro[oxetane-3,3'-pyrido[1,2-a]benzimidazole] and the azetidine ring-opened adduct, N-(2-acetamido-4-bromophenyl)-N-{[3-(chloromethyl) oxetan-3-yl]methyl}acetamide are disclosed.

Keywords: 4-membered rings; annulation; cyclization; diazole; heterocycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzimidazoles / chemical synthesis*
  • Benzimidazoles / chemistry
  • Crystallography, X-Ray
  • Cyclization
  • Ethers, Cyclic / chemical synthesis*
  • Ethers, Cyclic / chemistry
  • Oxidation-Reduction
  • Spiro Compounds / chemical synthesis*
  • Spiro Compounds / chemistry

Substances

  • Benzimidazoles
  • Ethers, Cyclic
  • Spiro Compounds
  • benzimidazole
  • oxetane