Extract ofFicus exasperataleaves was investigated as corrosion inhibitor of mild steel in 1 N H2SO4using conventional weight loss, electrochemical polarizations, electrochemical impedance spectroscopy and scanning electron microscopic studies. The weight loss results showed that the extract ofFicus exasperatais excellent corrosion inhibitor. Electrochemical polarizations data revealed the mixed mode of inhibition. The results of electrochemical impedance spectroscopy shows that the change in the impedance parameters, charge transfer resistance and double layer capacitance, with the change in concentration of the extract is due to the adsorption of active molecules leading to the formation of a protective layer on the surface of mild steel. Scanning electron microscopic studies provided the confirmatory evidence of improved surface condition, due to the adsorption, for the corrosion protection.

An alternative synthesis of piperazinomycin is disclosed. The approach is based on an intramolecular O-arylation of arylboronic acid with phenol for formation of the macrocyclic biaryl ether.

SummaryAn efficient synthesis of the angiotensin II receptor antagonist Telmisartan (1) is presented involving a cross coupling of 4-formylphenylboronic acid 10 with 2-(2-bromophenyl)-4,4-dimethyl-2-oxazoline (11) as the key step (90% yield). The benzimidazole moiety 15 was constructed regioselectively via a reductive amination-condensation sequence, replacing the alkylation of the preformed benzimidazole step in the previously published route. This methodology overcomes many of drawbacks associated with previously reported syntheses.

SummaryAn efficient synthesis of the angiotensin-II inhibitor valsartan (Diovan®) is presented. Directed ortho-metalation of 5-phenyl-1-trityl-1H-tetrazole (6) and its Negishi coupling with aryl bromide 5 are the key steps of the synthesis. This method overcomes many of the drawbacks associated with previously reported syntheses.

Titanium (IV) precursors anchored to alkyl substituted polyhedral oligomeric silsesquioxane (POSS) trisilanol and disilanol were prepared and characterized. These catalysts, formulated as, were found to be active in the polymerization of ethylene at high temperatures in combination with ethylaluminum sesquichloride (Et 3 Al 2 Cl 3 ) as a co-catalyst. The polyethylene products so obtained are linear, crystalline and display narrow dispersities. The effect of various reaction parameters on the catalyst performance is described.