5-Nitrobenzimidazole → methyl (E)-11-[2-(5-nitro-1-benzimidazolyl)ethylidene]-6,11-dihydrodibenz[b,e]oxepin-2-carboxylate

Participants

Reaction Steps

Compound h, 2.0 g, and 5.2 g of 5-nitrobenzimidazole were treated in a manner similar to Example 23 to give a 1:1 mixture of Compounds E-55a and E-56a. The mixture was separated and purified by silica gel column chromatography (eluting solvent, hexane:ethyl acetate:triethylamine=10:10:1) to give 1.1 g of methyl (E)-11-[2-(5-nitro-1-benzimidazolyl)ethylidene]-6,11-dihydrodibenz[b,e]oxepin-2-carboxylate (Compound E-55a) and 0.7 g of methyl (E)-11-[2-(6-nitro-1-benzimidazolyl)ethylidene]-6,11-dihydrodibenz[b,e]oxepin-2-carboxylate (Compound E-56a).

Provenance & Evidence