Synthesis of novel tricyclic pyrimidine-fused 5,6-dihydrobenzodiazepines via a Pictet–Spengler-like cyclization

Synthesis and catalytic evaluation of PVP-CeO2/rGO as a highly efficient and recyclable heterogeneous catalyst for multicomponent reactions in water

A highly efficient and eco-friendly route for the reduction of graphene oxide (GO) to reduced graphene oxide (rGO) was developed by using polyvinylpyrrolidone coated CeO₂ NPs (PVP-CeO₂) as a reducing and stabilizing agent. The resulting carbonaceous material, PVP-CeO₂/rGO, was well characterized with different spectroscopic techniques such as Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), elemental mapping, Transmission Electron Microscopy (TEM), Raman spectroscopy, powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), X-ray Photoelectron Spectroscopy (XPS), and Thermal Gravimetric (TG) analyses. The material exhibited high catalytic potential towards multicomponent reactions for the synthesis of biologically relevant benzodiazepine derivatives in aqueous media. The efficiency of the material for the desired reaction was shown in the form of an excellent product yield (96-98%) and a very short reaction time period (7-10 min). The use of water as solvent and recyclability of the catalyst made the present protocol acceptable from a green perspective.

The discovery of kinase inhibitors by a combination of diversity-oriented synthesis and selective screening

An efficient strategy for the discovery of kinase inhibitors by a combination of diversity-oriented synthesis and selective screening was presented.

Synthesis of novel 8,9-dihydro-5H-pyrimido[4,5-e][1,4]diazepin-7(6H)-ones

Practical and efficient methods have been developed for the synthesis of 4,6,8,9-tetrasubstituted 8,9-dihydro-5H-pyrimido[4,5-e][1,4]diazepin-7(6H)-ones from 4,6-dicholoropyrimidine aldehyde, N-substituted amino acid esters, and amines in five steps. This synthetic strategy is based on suitably substituted pyrimidines as bis-electrophilic species reacting with various amines to construct the pyrimido[4,5-e][1,4]diazepine core with a strategically anchored functional group for further derivatization. The utility of this methodology was demonstrated through the preparation of a 33-membered library of representative 8,9-dihydro-5H-pyrimido[4,5-e][1,4]diazepin-7(6H)-ones in good to excellent yields.

Synthesis of Benzonaphtho[1,4]Diazepine Derivatives via the Reaction of 2-Aminoarylbenzimidamides with 2,3-Dichloro-1,4-Naphthoquinone

A series of (Z)-13-(arylimino)-12,13-dihydro-5H-benzo[e]naphtho[2,3-b][1,4]diazepine-6,11-dione derivatives have been synthesised by one pot cyclisation in good yield via electron donor–acceptor complexes by reacting 2-aminoarylbenzimidamides with 2,3-dichloro-1,4-naphthoquinone. The high yield and simplified workup procedure in addition to the mild and neutral reaction conditions are the main advantages of this approach.

A Cascade Reaction Consisting of Pictet−Spengler-Type Cyclization and Smiles Rearrangement: Application to the Synthesis of Novel Pyrrole-Fused Dihydropteridines

[reaction: see text] Tandem Pictet-Spengler-type cyclization and Smiles rearrangement have been discovered in the synthesis of pyrimidine-fused heterocycles. The reaction of 4-chloro-5-pyrrol-1-ylpyrimidine amino aldehyde with an amine under an acidic condition yielded the Pictet-Spengler-type cyclization product diazepine, which readily underwent Smiles rearrangement to give a novel pyrrolo[1,2-f]pteridine derivative.

Design and Synthesis of a Tetracyclic Pyrimidine-Fused Benzodiazepine Library

Method development for a heterocyclic library which entails novel scaffolds of benzodiazepines fused with various heterocycles, such as pyrimidines, indolines, and tetrahydroquinolines, was accomplished. The new synthetic strategy is based on an electrophilic cyclization reaction involving an iminium intermediate formed by the corresponding aminopyrimidine with a carbonyl compound to give the desired heterocycles in high yields. Subsequent replacement of the chloro group in the resulted structures with a nucleophile, such as boronic acids, amines, alcohols and thiols, led to a library of privileged compounds with up to eight accessible diversity points.