Reaction of 5-nitrospiro[benzimidazole-2,1′-cyclohexane] 1,3-dioxide with electrophilic reagents: Bromine and nitric acid

• Published in: Russian journal of organic chemistry Vol. 49; no. 8; pp. 1208 - 1214
• Main Authors: Samsonov, V. A., Gatilov, Yu. V., Savel’ev, V. A.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.08.2013; Springer Nature
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry, Organic; Organic Chemistry; Physical Sciences; Science & Technology; Bromine; Furoxane; Benzimidazole; Cyclohexane; Electrophilic Substitution
• ISSN: 1070-4280; 1608-3393
• DOI: 10.1134/S1070428013080198

Reactions of 5-nitrospiro[benzimidazole-2,1′-cyclohexane] 1,3-dioxide with bromine and nitric acid lead to the electrophilic substitution of the hydrogen atom in the meta -position with respect to the nitro group. At thebromination the primarily formed 4-bromo-6-nitrospiro[benzimidazole-2,1′-cyclohexane] 1,3-dioxide when kept in the solution loses an oxygen atom forming 4-bromo-6-nitrospiro[benzimidazole-2,1′-cyclohexane] 1-oxide and an isomerization product, 8-bromo-6-nitrospiro[3 H -[2,1,4]benzoxadiazine-3,1′-cyclohexane] 4-oxide. The latter exposed to light turns into 4-bromo-6-nitrospiro[benzimidazole-2,1′-cyclohexane] 1,3-dioxide. The reaction of the initial 1,3-dioxide with nitric acid afforded 4,6-dinitrospiro[benzimidazole-2,1′-cyclohexan]-7-ol 1-oxide whose heating in o -dichlorobenzene resulted in 3,5-dinitro-1,8-diazatricyclo[7.5.0.0 2,7 ] tetradeca-2(7),3,5,8-tetraen-6-ol.