A concise synthesis of a highly substituted 6-(1H-benzimidazol-1-yl)-5-nitrosopyrimidin-2-amine: synthetic sequence and the molecular and supramolecular structures of one product and two intermediates

作者：Cobo Justo; Vicentes Daniel E; Rodriguez Ricaurte; Marchal Antonio; Glidewell Christopher^*

来源：Acta Crystallographica Section C-Structural Chemistry, 2018, 74(6): 696-+.

DOI：10.1107/S2053229618007015

• synthesis
• heterocyclic compound
• nitrosopyrimidine
• benzimidazole
• molecular structure
• electronic polarization
• hydrogen bonding
• supramolecular aggregation
• crystal structure

A concise and efficient synthesis of 6-benzimidazolyl-5-nitrosopyrimidines has been developed using Schiff base-type intermediates derived from N-4-(2-amino-phenyl)-6-methoxy-5-nitrosopyrimidine-2,4-diamine. 6-Methoxy-N-4-{2-[(4-methyl-benzylidene) amino]phenyl}-5-nitrosopyrimidine-2,4-diamine, (I), and N-4-{2-[(ethoxymethylidene)amino]phenyl}-6-methoxy-5-nitrosopyrimidine-2,4-diamine, (III), both crystallize from dimethyl sulfoxide solution as the 1:1 solvates C19H18N6O2 center dot C2H6OS, (Ia), and C14H16N6O3 center dot C2H6OS, (IIIa), respectively. The interatomic distances in these intermediates indicate significant electronic polarization within the substituted pyrimidine system. In each of (Ia) and (IIIa), intermolecular N-H center dot center dot center dot O hydrogen bonds generate centrosymmetric four-molecule aggregates. Oxidative ring closure of intermediate (I), effected using ammonium hexanitratocerate(IV), produced 4-methoxy-6-[2-(4-methylphenyl-1H-benzimidazol-1-yl]-5-nitrosopyrimidin-2-amine, C19H16N6O2, (II) [Cobo et al. (2018). Private communication (CCDC 1830889). CCDC, Cambridge, England], where the extent of electronic polarization is much less than in (Ia) and (IIIa). A combination of N-H center dot center dot center dot N and C-H center dot center dot center dot O hydrogen bonds links the molecules of (II) into complex sheets.

• 出版日期2018-6