Palladium(II)-mediated coupling reactions of bromo- and iodo-1H-1,4-benzodiazepine-2,5-diones. A route to functionalized benzodiazepinediones

Multicomponent reactions as a potent tool for the synthesis of benzodiazepines

Benzodiazepines (BZDs), a diverse class of benzofused seven-membered N-heterocycles, display essential pharmacological properties and play vital roles in some biochemical processes. They have mainly been prescribed as potential therapeutic agents, which interestingly represent various biological activities such as anticancer, anxiolytic, antipsychotic, anticonvulsant, antituberculosis, muscle relaxant, and antimicrobial activities. The extensive biological activities of BZDs in various fields have encouraged medicinal chemists to discover and design novel BZD-based scaffolds as potential therapeutic candidates with the favorite biological activity through an efficient protocol. Although certainly valuable and important, conventional synthetic routes to these bicyclic benzene compounds contain methodologies often requiring multistep procedures, which suffer from waste materials generation and lack of sustainability. By contrast, multicomponent reactions (MCRs) have recently advanced as a green synthetic strategy for synthesizing BZDs with the desired scope. In this regard, MCRs, especially Ugi and Ugi-type reactions, efficiently and conveniently supply various complex synthons, which can easily be converted to the BZDs via suitable post-transformations. Also, MCRs, especially Mannich-type reactions, provide speedy and economic approaches for the one-pot and one-step synthesis of BZDs. As a result, various functionalized-BZDs have been achieved by developing mild, efficient, and high-yielding MCR protocols. This review covers all aspects of the synthesis of BZDs with a particular focus on the MCRs as well as the mechanism chemistry of synthetic protocols. The present manuscript opens a new avenue for organic, medicinal, and industrial chemists to design safe, environmentally benign, and economical methods for the synthesis of new and known BZDs.

Facile synthesis of 1,4-benzodiazepine-2,5-diones and quinazolinones from amino acids as anti-tubercular agents

A family of 1,4-benzodiazepine-2,5-diones and quinazolinones with diverse substituents at C-3 position are synthesized by novel, simple and convenient methodology using H₂PtCl₆as catalyst and were all screened for anti-TB activity.

Equimolar carbon absorption by potassium phthalimide and in situ catalytic conversion under mild conditions

Potassium phthalimide, with weak basicity, is an excellent absorbent for rapid carbon dioxide capture with almost equimolar absorption. This process is assumed to proceed through the potassium carbamate formation pathway, as supported by NMR spectroscopy, an in situ FTIR study, and computational calculations. Both the basicity and nucleophilicity of phthalimide salts have a crucial effect on the capture process. Furthermore, the captured carbon dioxide could more easily be converted in situ into value-added chemicals and fuel-related products through carbon capture and utilization, rather than going through a desorption process.

An Expeditious Route to Novel 1,4,2-Benzodiazaphosphepin-5-one 2-Oxide Analogues

A short and efficient synthesis of the novel 1,4,2-benzodiazaphosphepin-5-one 2-oxide ring system, a phosphonamidate isostere of the 1,4-benzodiazepine-2,5-dione system, has been carried out in good overall yield. The key step is the base-induced cyclization of (2-aminobenzamido)methylphosphonates 6a-c to the 1,4,2-benzodiazaphosphepin-5-one 2-oxides 7a-c. Alkylation of 7b with methyl iodide gives the expected N-methyl analogue 9. When a tandem one-pot cyclization/alkylation is carried out from 6b in the presence of excess base, the sole isolable product obtained is the phosphonate 13, presumably via ethanolysis of a transiently formed 9. Carrying out the tandem cyclization/alkylation in the absence of excess base, however, affords only 9. Thionation of 7 with Lawesson's reagent occurs at either the phosphonamidate oxygen (P-2) or the amide carbonyl (C-5) depending on the steric constraint of the N-4 substituent.