Solid support based synthesis of 1,5-benzodiazepines: A mini review

A Stereoselective Synthesis of a Novel α,β-Unsaturated Imine-Benzodiazepine through Condensation Reaction, Crystal Structure, and DFT Calculations

The stereoisomers (E)-2,2-dimethyl-4-(4-subsitutedstyryl)-2,3-dihydro-1H-[1,5]-benzodiazepine 3(a-d) were synthesized via the condensation reaction of 2,2,4-trimethyl-2,3-dihydro-1H-1,5-benzodiazepine (BZD) 1 with the benzaldehyde derivatives 2(a-d) in ethanol. The chemical structure of the prepared products was confirmed by NMR (1H and 13C), HRMS, and X-ray analysis of the crystal structure 3d. The condensation reaction was examined using DFT calculations at the theoretical level of B3LYP/6-31G(d) to elucidate the chemo-, regio-, and stereoselectivity and the reaction mechanism of the produced isomer. Furthermore, we identified each reagent's reactive sites by the measurement of the reactivity indices. We also looked at how the electron-withdrawing groups (EWGs) of various aldehydes affected the reaction's mechanism and the stability of products 3(a-d).

Synthetic aspects of 1,4- and 1,5-benzodiazepines using o-phenylenediamine: a study of past quinquennial

Benzodiazepines, seven-membered heterocyclic compounds having two nitrogen atoms at different positions, are ruling scaffolds in the area of pharmaceutical industry. They act as cardinal moieties in organic synthesis as well as in medicinal chemistry. Among the different benzodiazepines, 1,4- and 1,5-benzodiazepines play a far-reaching role in the field of biological activities such as anticonvulsion, anti-anxiety, sedation, and hypnotics. In the past few decades, researchers have conducted a lot of work on these moieties and developed broad, valuable, and significant approaches for their synthesis. In this review article, we recapitulate the systematic synthetic strategies of 1,4- and 1,5-benzodiazepines using o-phenylenediamine as a precursor over the past five years (2018-2022). This article will be helpful for scientists and researchers to examine and explore novel and efficient methods for the synthesis of these biologically active moieties.