Hard and soft electrophilic and nucleophilic dissymmetry of α-oxoketenedithioacetals and p-nitro-o-phenylenediamine exploited to achieve the regioselectivity in the synthesis of 2-thiomethyl ether substituted isomer of the privileged nucleus of 1,5-benzodiazepines over to its 4-substituted isomers

Abstract

Hard and soft electrophilic and nucleophilic dissymmetry of α-oxoketenedithioacetals and p-nitro-o-phenylenediamineexploited to achieve the regioselectivity in the synthesis of 2-thiomethyl ether substituted isomer of the privileged nucleus of 1,5-benzodiazepines over to its 4-substituted isomersAbstract. An exclusive regioselective formation of 2-thiomethyl ether substituted isomer of the privileged nucleus of 1,5-benzodiazepines was achieved from the reaction of p-nitro-o-phenylenediamine with a variety of α-oxoketene dithioacetals derived from several active methylene compounds, by exploiting the strategy based on the variation of electrophilicity of the two electrophilic centers of α-oxoketene dithioacetals and the hard and soft nucleophilic profiles of the p-nitro substituted o-phenylenediamines.Keywords. Regioselectivity in synthesis; 1,5-benzodiazepines; α-oxoketene dithioacetals; hard and soft dissymmetry of electrophilic and nucleophilic species.

Heteroring Annulated Benzimidazolinone Condensed Azepinone Derivatives: A New Class of Highly Potent Antioxidants

“…There has been considerable interest on the heterocyclic systems bearing such pharmacophoric scaffolds in their molecules, with regard to their chemistry and the pharmacological activity. Literature is replete with a wide variety of examples of one pot synthesis of heterocyclic systems bearing five, six, and seven membered rings from the corresponding oxoketene dithioacetals derivatives [5,7].…”

“…We envisioned that this concept could be applied in our synthetic work by utilizing the potential of a novel building block developed from the benzimidazolinone condensed analogue of azepinone 2 which could be realized in two simple steps from benzimidazolinone nucleus involving first its reaction with succinic anhydride followed by its cyclocondensation with acid. We utilized the inherent potential of this building block in heteroannulation of its face "d" with such heterocyclic scaffolds as pyrazole, isoxazole [1][2][3], pyrimidine [4], benzodiazepine [5], and benzothiazepine [6] which had the previous history of being highly biologically active in the literature.…”