Reaction of the Fischer base with 8-hydroxy-1-naphthaldehydes. Investigation of the reaction products by 13C NMR spectroscopy

The product of the condensation of the Fischer base with unsubstituted 8-hydroxy-1-naphthaldehyde is a bisindolinespirooxepine. 5,7-Dinitro-8-hydroxy-1-naphthaldehyde reacts with the Fischer base to give a merocyanine that does not display a tendency to undergo conversion to the cyclic form. 2H-Naphtho[1,8-bc]furan derivatives are formed in the reaction of the Fischer base with 5-nitro-, 5-bromo-, and 5,7-dibromo-8-hydroxy-1-naphthaldehydes. The structures of the compounds obtained were established on the basis of data from the PMR and ¹³C NMR spectra. It was shown by means of the ¹³C NMR spectra that the product of the condensation of phthalic monoaldehyde with the Fischer base is not a seven-membered spirolactone, as previously assumed, but rather a phthalide derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1501–1506, November, 1982.     

Pyrrolophenoxathiin dioxides. 1. Synthesis of 3H-pyrrolo[2,3-c]phenoxathiin 11,11-dioxide and 1h-pyrrolo[3,2-b]phenoxathiin 10,10, dioxide by the fischer reaction

Cyclization of the 2 phenoxathiin 10,10-dioxide hydrazone of ethyl pyruvate in ethyl polyphosphate results in the concurrent formation of the respective cyclic esters of both angular and linear structures. The parent compounds of a new condensed heterocyclic system of pyrrolophenoxathiin dioxides are synthesized from the latter.Georgian Technical University, Tbilisi 380075. D. I. Mendeleev Russian Chemical Engineering University, Moscow 125047. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 409–412, March, 1996. Original article submitted July 1, 1995.     

Synthesis of 4-chlorosubstituted spiropyranes of the indole series

Enaminohydroxyketones, formed from 1,3,3-trimethyl-2-methyleneindoline and ortho-acetoxyaromatic acid chlorides, are converted by heating with phosphorus oxychloride in dichloroethane and subsequent treatment with alkali to 4-chlorosubstituted spiropyranes of the indole series; these, in contrast to the unsubstituted analogs, do not show photochromic properties.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1346–1349, October, 1987.     

Use of PM6 quantum-chemical calculations in studying the properties of antioxidants in the biological environment

The energies of formation, enthalpies, and entropies of the conformers of 1-(carboxy)-1-(N-methylamide)-2-(3′,5′-di-tert-butyl)-4-hydroxyphenyl)-propionic acid and sodium and potassium 1-(carboxy)-1-(N-methylamide)-2-(3′,5′-di-tert-butyl)-4-hydroxyphenyl)-propionates are calculated by quantum-chemical methods in the PM6 approximation. A doubling of signals in the ¹H NMR spectrum of the first conformer is observed, which merge into singlets when the compound is heated. Changes in the structure of the conformers and donor-acceptor complexes (solvates) occur with the preservation of the metal-ligand coordination bond. Calculations of the characteristics of 1-(carboxy)-1-(N-methylamide)-2-(3′,5′-di-tert-butyl)-4-hydroxyphenyl)-propionic acid and sodium and potassium 1-(carboxy)-1-(N-methylamide)-2-(3′,5′-di-tert-butyl)-4-hydroxyphenyl)-propionates in the PM6 approximation make it possible to predict the structure and properties of the solvated structures. The energies of homolysis of the H-O bond D _(OH) are calculated, and a linear dependence of the antioxidant activity on D _(OH) for the structures of the studied compounds is demonstrated. The results make it possible to predict the properties of antioxidants in the biological environment.