2H-Azirine-2-carbonyl azides, new reactive heterocyclic building blocks, were synthesized in high yield by the reaction of sodium azide with 2H-azirine-2-carbonyl chlorides, generated by the Fe­(II)-catalyzed isomerization of 5-chloroisoxazoles. 2-(Azidocarbonyl)-1H-pyrroles, prepared by the Ni­(II)-catalyzed reaction of 2-(azidocarbonyl)-2H-azirines with 1,3-diketones, easily undergo the Curtius rearrangement in boiling tBuOH to give Boc-protected α-aminopyrroles in high yield. Heating of 2-(azidocarbonyl)-1H-pyrroles for a short time in inert solvents leads to the high-yield formation of benzo- and hetero-fused 1H-pyrrolo­[2,3-b]­pyridin-6­(7H)-ones, which are formed via a 6π electrocyclization involving the vicinal aryl or hetaryl substituent and the NC bond of isocyanate, generated by the Curtius rearrangement of the azidocarbonyl group. The Pd-catalyzed cross-coupling reaction of 1-acetyl-2-methyl-3H-pyrrolo­[2,3-c]­isoquinolin-5-yl triflate, easily prepared from the corresponding pyrroloisoquinolone, leads to variously 5-substituted 3H-pyrrolo­[2,3-c]­isoquinolines in excellent yields.

Azirine-triazole hybrids, 1-R-5-(3-aryl-2H-azirin-2-yl)-1H-1,2,3-triazoles, were selectively synthesized by reaction of 1-(3-aryl-2H-azirin-2-yl)-2-(triphenylphosphoranylidene)ethanones with tosyl and (E)-2-benzoylvinyl azides in high yields at rt. The reaction with 2-azidopyridine makes it possible to obtain azirine-triazole-pyridine...

Аналитика и контроль. 2019. Т. 23. № 2. the equal amounts of additional standard are added to the equal amounts of samples; the peak ratios (S x / S add.stand) and (S stand /S add.stand) are used in the subsequent data processing. This modified external standard method is not described in the contemporary scien tific and teaching literature on gas chromatography. Thus, for the illustration of its advan tages, the results of target analyte quantification in different solvents using basic and modified methods are compa red in the cur rent study. All measurements were carried out by the senior students of the Institute for Chemistry of St. Petersburg State University (Russia) during their practical exercises in gas chromatography. It was shown that the modified external standard method compared with its basic ver sion provided better repeatability of determinations, better precision (lesser systema tic errors) and reduced the overall time expenses due to the lesser quantity of serial ana lyses and the absence of the necessity to reveal and exclude the outliers.