Atropisomerism in 4-(2-thienyl)-4H-1,2,4-triazole derivatives

Article abstract of DOI:10.1248/cpb.40.220

3-Aminomethyl-4-[3-(o-chlorobenzoyl)-5-ethylthiophen-2-yl]-5-methyl-4H- 1,2,4-triazole (I), the hydrolytically ring-opened derivative of etizolam, which is one of the 1,4-diazepine antianxiety drugs, was investigated from the stereochemical point of view. In order to isolate atropisomers of compound I, its carbonyl group was reduced to a chiral secondary alcohol. The resulting compounds were resolved successfully into two components (IIa and IIb) bv silica-gel column chromatography. The structures of atropisomeric IIa and IIb, possessing rotational differences about the single bond between the thiophene and triazole rings, were confirmed by X-ray crystallographic analysis. The interconversion behavior between them was also examined.

Full text of DOI:10.1248/cpb.40.220

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NII-Electronic Library Service

NII-Electronic Library Service

NII-Electronic Library Service