Synthesis and chiral separation of atropisomers of 4,5‐Di methyl ∆<sup>4</sup> N‐phenyl N‐aryl imidazoline‐2‐thione derivatives
Aicha Laoufi, Nasser Belboukhari, Khaled Sekkoum, Hassan Y. Aboul‐Enein
Abstract
Abstract Synthesis of three chiral 4,5‐Di methyl ∆ 4 N‐phenyl N‐aryl imidazole‐2‐thione derivatives was obtained by the condensation reaction of thiourea derivatives with α‐hydroxy ketone. The structure of these compounds has been characterized by using spectroscopic methods (UV, IR, 1 H NMR, and 13 C NMR). The 4,5‐Di methyl ∆ 4 N‐phenyl N‐aryl imidazole‐2‐thiones display a chiral axis around the N‐C bond linking between the nitrogen of the heterocyclic framework and the carbon of the aryl group. Screening on chiral analysis of the atropisomers of these derivatives was performed by high‐performance liquid chromatography method on seven chiral selectors based on polysaccharides consisting of amylose and cellulose, namely, Chiralpak®AD, Chiralcel® OD, Chiralcel® OD‐H, Chiralcel® OJ, Chiralcel® OD‐3R, Chiralcel® OZ‐3, and Chiralpak® AS‐3R. The impact of ortho‐substituent in the resolution of 4,5‐Di methyl ∆ 4 N‐phenyl N‐aryl imidazole‐2‐thione derivatives was also studied in this work .