An efficient synthesis of highly substituted pyrrole and bis pyrrole derivatives

An efficient synthesis of highly substituted pyrrole and bis pyrrole derivatives is reported.     

Synthesis and spectroscopic properties of isomeric trideuterio‐ and tetradeuterio pyridines

The syntheses of the six possible isomeric trideuteriopyridines and the three possible isomeric tetradeuteriopyridines are described. These deuteriopyridines were characterized by their mass and NMR spectra.     

Studies with enamines and azaenamines: A novel efficient route to 6‐amino‐1,4‐dihydropyridazines and their condensed derivatives

1‐Arylhydrazonopyruvaldehydes 1 react with α,β‐unsaturated nitriles 2 to yield 6‐amino‐1,4‐dihydropyridazines 4 that are converted into pyridazinones 5 via refluxing in an acetic acid/hydrochloric acid mixture and into the ethylidenemalononitrile derivatives 6 on reflux with malononitrile in ethanolic/piperidine solution.     

Control of Duplex Formation and Columnar Self‐Assembly with Heterogeneous Amide/Urea Macrocycles

The perfect blend : A new class of self‐assembling cyclooligomers with mixed urea/amide backbone is described (see figure). A high level of hierarchical and directional control is achieved: depending on the level of backbone preorganization, columnar or tubular arrangements with either parallel or antiparallel growing modes can be selected.

     

Polystyrene‐supported AICI3: A highly active and reusable heterogeneous catalyst for the one‐pot synthesis of dihydropyrimidinones

An environmentally benign Biginelli protocol for the one‐pot synthesis of substituted 3,4‐dihydropyrimidin‐2(1H)‐ones using polystyrene supported aluminium chloride as catalyst has been achieved. This polymeric catalyst is stable and can be easily recovered and reused without obvious change in their efficiency.     

A convenient synthesis of 5‐alkylthio‐3,4‐diarylisoxazoles by palladium‐catalyzed coupling reactions

Palladium‐catalyzed coupling reaction was found effective for rapid access to pharmacologically interesting 3,4‐diarylisoxazoles derivatives as selective COX‐2 inhibitors. Thus, the coupling reaction between 5‐alkylthio‐3‐aryl‐4‐iodoisoxazoles and arylboronic acids afforded the target 5‐alkylthio‐3,4‐diarylisoxazoles in good yields.     

Gas‐phase thermolysis of benzotriazole derivatives. Part 4. Pyrolysis of 1‐acylbenzotriazole phenylhydrazones. Interesting direct routes towards N‐aminobenzimidazoles

Flash vacuum pyrolysis (FVP) of 1‐acylbenzotriazole phenylhydrazones gave benzonitriles, aniline and 2‐arylbenzimidazole derivatives. Static pyrolysis of the same substrates at 180 °C gave exclusively the corresponding N‐anilino‐2‐arylbenzimidazole derivatives. Pyrolysis of the isomeric 2‐acylbenzotriazole phenylhydrazones gave similar products.