- New chemical markers based on phthaleins
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New chemical markers based on mixtures of individual phthaleins were developed. These markers are characterized by high level of secrecy in use, good transferability to contacting persons, enhanced retention on the objects marked, and reliable identification of phthaleins by expert investigation. The experimental studies of the markers obtained show that the synthesized mixture of three phthalein homologs contains the previously unknown phthalein with unsymmetrical phenolic substituents, o-cresolphenolphthalein [3-(3′-methyl-4′-hydroxyphenyl)-3-(4?-hydroxyphenyl)phthalide], which decreases the probability of the marker falsification. Quantum-chemical calculations of the reaction of the o-cresolphthalein synthesis show that the overall reaction is characterized by small positive changes in the enthalpy and Gibbs free energy, and the second and third steps occur with negative changes in the Gibbs energy. The optimum structure of the transition state was calculated.
- Nekhoroshev,Nekhoroshev,Poleshchuk,Yarkova,Nekhorosheva,Gasparyan
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p. 711 - 718
(2015/08/03)
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- 3,3-Diarylphthalides. Part I. Friedlaender reaction of 3′-alkylphenolphthaleins
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Friedlaender reaction was investigated, starting from 3′-alkyl-derivatives of phenolphthalein 1-3 (alkyl = Me, Et and i-Pr) and hydroxylamine in strongly alkaline medium. The process was found to give, after acidic hydrolysis of primarily formed anil-type semi-products, a mixture of two 2-aroylbenzoic acids (2-ABAs) in each case. Identification and quantification of 2-ABAs were carried out within RP-HPLC on ODS column. Based on quantitative results, migratory aptitude (MA) parameter values of ionized 4-hydroxy-3-alkylphenyl nuclei were calculated, taking an unsubstituted ionized 4-hydroxyphenyl ring as a standard.
- Ruminski
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p. 908 - 914
(2007/10/03)
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