Unexpected opening of benzimidazole derivatives during 1,3-dipolar cycloaddition

1-Nonyl-1H-benzimidazol-2(3H)-one

“…For the pharmacological and biochemical properties of benzimidazol-2-one derivatives, see: El Azzaoui et al (2006); Soderlind et al (1999); Ré mond et al (1997); Gribkoff et al (1994); Olesen et al (1994); McKay et al (1994). For hydrogen-bond motifs, see: Etter et al (1990); Bernstein et al (1995).…”

Crystal structure of 2-((5-methyl-1-(pyridin-2-yl)-1H-pyrazol-3-yl)- methyl)-1H-benzo[d]imidazolecadmium(II) dichloride, Cd(C17H15N5)Cl2

“…For example, the 5,6-dichloro-2-(isopropylamino)-1-1,b-L-ribofuranosyl-1-Hbenzimidazole is anovel benzimidazole derivative for treatment of human cytomegalovirus (HCMV) infection and disease [1,2]. On the other hand, transition metal complexes with benzimidazole and its derivatives have attracted much attention due to interesting structural [3] and chemical properties [4], as well as due to their potential applications in biology [5] and material science [6]. The title crystal strucure is monomeric with the cadmium atom in afive-coordinate arrangement that is best described as adistorted trigonal bipyramide.…”

Addition Reactions: Cycloaddition

“…49 The intramolecular 1,3-dipolar cycloadditions of homochiral nitrilimines derived from methyl esters of glycine, l-alanine, l-phenylalanine, and (S)-2-phenylglycine produced enantiopure 2,3,3a,4,5,6-hexahydropyrrolo [3,4-c]pyrazoles in fair to good overall product yields. 50 The thermal reaction of diphenylnitrilimine with Nsubstituted benzimidazoles (47) produced N ,N -disubstituted o-phenylenediamines (51). The reaction involved two 1,3-dipolar cycloadditions with two nitrilimine moieties yielding adducts (48)(49)(50), followed by a ring opening of the azolic ring of (50) (Scheme 13).…”

“…The reaction involved two 1,3-dipolar cycloadditions with two nitrilimine moieties yielding adducts (48)(49)(50), followed by a ring opening of the azolic ring of (50) (Scheme 13). 51 The chemo-, regio-, and stereo-selective 1,3-dipolar cycloaddition of C-aryl-Nphenylnitrones with 3,5-bis(arylidine)-1-methylpiperidin-4-ones produced mono-and bis-spiroisoxazolidines, with the former predominating. 52 The 1,3-dipolar cycloaddition of five-membered cyclic nitrones with α,β-unsaturated γ -lactones provides an interesting example of a double asymmetric induction.…”