76895-89-1

Upstream product

• 85-44-9 phthalic anhydride 
• 137-07-5 2-amino-benzenethiol 
• 88-99-3 benzene-1,2-dicarboxylic acid 
• 1141-88-4 2-Aminophenyl disulfide 

Relevant academic research and scientific papers

Ti (IV) complexes of some heterocyclic ligands synthesis, characterization and ethylene polymerization activity

31 complexes of bis - (benzimidazole, benzothiazole and benzoxazole) compounds with Ti (IV) metal centers were synthesized, characterized, activated with methylalumoxane (MAO) and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the hetero atoms in the ligand frameworks. The highest activity was obtained with 39/MAO (573 kg PE/mol cat. h). The produced polyethylenes showed high molecular weights (up to 1.5 × 106 g/mol) and broad molecular weight distributions (PD = 65). This could result from different interactions of the MAO counterion with the heteroatoms of the catalyst ligand generating different active sites.

Zr(IV) complexes of some heterocyclic ligands: Synthesis, characterization, and ethylene polymerization activity

Thirty-one complexes of bis-(benzimidazole, benzothiazole, and benzoxazole) compounds with Zr(IV) metal centers were synthesized, characterized, activated with methylaluminoxane (MAO), and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the heteroatoms in the ligand frameworks and the structure around the active metal center. The highest activity was obtained with 38/MAO (424 kg E/mol cat. h). The produced polyethylenes showed high molecular weights (41/MAO, 1.9 × 106 g/mol) and broad molecular weight distributions (38/MAO, Mw = 9.64 × 105 g/mol, PD = 23). This could result from different interactions of the MAO counter ion with the heteroatoms of the catalyst ligand generating different active sites.

Bis(benzimidazolyl, benzothiazolyl, and benzoxazolyl)benzene complexes as catalysts for ethylene polymerization

A series of 36 complexes of 1,2-bis(benzimidazolyl, benzothiazolyl and benzoxazolyl)benzene compounds with Ti(IV), Zr(IV) and V(III) were synthesized and characterized. After activation with methylaluminoxane (MAO), they showed variable activities towards ethylene polymerization. Parameters like the steric conditions and the number and nature of the hetero atoms at the precatalyst molecule, the concentration of the cocatalyst MAO, the nature of the transition metal and the reaction temperature have a strong influence on the performance of the corresponding catalysts. The polymerization activity of the catalyst system [1,2-bis(benzimidazolyl)benzene zirconium tetrachloride] 20/MAO was investigated under various polymerization conditions. Studies of structure-property relationships allowed the optimization of catalysts. Bimodal or multimodal resins indicate the existence of more than one active site in the polymerization reaction in one type of homogeneous catalyst.

Metal-free synthesis of benzothiazoles from disulfides of 2-aminobenzenethiol and carboxylic acid via PCl3-promoted tandem reaction

A metal-free process for the synthesis of benzothiazoles via PCl3-promoted cleavage/acylation/ cyclization of disulfides and carboxylic acids has been developed. In addition to acting as the acylating reagent which converted carboxylic acids into acyl chlorides, PCl3 also converted disulfides to thiols, which promoted disulfides of 2-aminobenzenethiol reacted with carboxylic acid to produce benzothiazoles. The developed method is applicable to a wide range of carboxylic acids containing different functional groups.

An efficient synthesis of benzothiazoles by direct condensation of carboxylic acids with 2-aminothiophenol under microwave irradiation

Carboxylic acids are converted to benzothiazoles by direct condensation with 2-aminothiophenol under microwave irradiation in the absence of solvent.