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An efficient synthesis of 1-vinyl/arylbenzotriazole 3-oxides via the copper-promoted coupling of N-hydroxybenzotriazoles with alkenyl-o r arylboronic acids is reported. This strategyf eatures mild reactionc onditions,g oodf unctional group tolerance,b road substrate scope and rapid introduction of benzotriazole N-oxide moieties into molecules.D ensity functional theory calculations revealed that the formation of the favored N-coupling product depends on the kinetically more favorable C-N bond formation pathway.

A rapid, simple, and specific liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) method has been developed and validated for the determination of lisinopril in human plasma. Enalaprilat was used as the internal standard (IS). Sample preparation of the serum involved deproteination with methanol twice, repeatedly. Samples were separated using a Thermo Hypersil-HyPURITY C18 reversed-phase column (150 x 2.1 mm i.d., 5 microm). Mobile phase consisted of formic acid solution (pH 2.9)-methanol-acetonitrile (58:25:17, v/v). Lisinopril and its internal standard were measured by electrospray ion source in positive selected ion monitoring mode. The method was validated with a linear range of 2.5-320 ng/mL and the lowest limits of quantitation were 2.5 ng/mL for lisinopril. The extraction efficiencies were approximately 80% and recoveries of method were in range of 94.4-98.2%. The intra-day relative standard deviation (RSD) was less than 8.8% and inter-day RSD was within 10.3%. QC samples were stable when kept at ambient temperature for 24 h, at -20 degrees C for 30 days and after four freeze/thaw cycles. The method has been successfully applied to the evaluation of pharmacokinetics and bioequivalence of 2 lisinopril formulations in 18 healthy Chinese volunteers after an oral dose of 20 mg.

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A tunable strategy to prepare α,β‐unsaturated esters and α,β‐unsaturated‐γ‐keto esters in good to excellent yields was developed through copper‐catalyzed oxidative coupling of phosphorus ylides with alkenyl boronic acids under mild conditions. The reaction without water afforded α,β‐unsaturated esters, ketones, and amides while α,β‐unsaturated‐γ‐keto esters, 1,4‐α,β‐unsaturated diketones and α,β‐unsaturated‐γ‐keto amides were obtained when using 5.0 equiv. of water. H2O18 labeling experiments showed that water played an important role in the formation of α,β‐unsaturated‐γ‐keto esters. A plausible formation mechanism for α,β‐unsaturated esters and α,β‐unsaturated‐γ‐keto esters was proposed based on mechanistic studies. Phosphonium salts could also be used directly as coupling partners instead of phosphorus ylides. The reaction exhibited a broad substrate scope, good functional group tolerance, good regioselectivity, and diverse coupling products.magnified image

A variety of 2-(3-methyleneindolin-2-yl)phenols were prepared in good to excellent yields through a NaH-promoted C–C/C–O bond cleavage of fused indolines under mild and simple conditions. Mechanistic studies showed that NaH serves as a nucleophile, attacking the aldehyde group of indoline, which is followed by tandem C–C/C–O bond cleavage to afford the desired products. A representative 2-(3-methyleneindolin-2-yl)phenol was easily prepared on a gram scale.