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Esikov, K. A.; Morozova, S. E.; Malin, A. A.; Островский, В. А.

doi:10.1023/a:1021624401405

Cited by 23 publications

(9 citation statements)

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“…The system SiCl 4 -NaN 3 ensures preparation of both 1,5-disubstituted [6] and 1-unsubstituted tetrazoles [5,6], and it can be applied to various substrates, amino acids among these. Following this procedure, tetrazole-containing analogs of (D,L)-phenylalanine, (D,L)-leucine [7], and (D,L)-tryptophane [8] were synthesized.We have extended the above approach to the synthesis of structures containing both two and three tetrazole rings. As starting compound we used previously synthesized ditetrazole I [7].…”

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confidence: 99%

“…Following this procedure, tetrazole-containing analogs of (D,L)-phenylalanine, (D,L)-leucine [7], and (D,L)-tryptophane [8] were synthesized.…”

mentioning

confidence: 99%

“…As starting compound we used previously synthesized ditetrazole I [7]. It was treated with chloroacetamide in the presence of triethylamine to obtain tetrazolylacetamide II, and reaction of the latter with the system tetrachlorosilane-sodium azide gave compound III containing three differently substituted tetrazole rings.…”

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confidence: 99%

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confidence: 99%

“…By alkaline hydrolysis of II we obtained tetrazolylacetic acid IV (Scheme 2). The syntheses were performed according to the procedures RCONHR [7,8]. The alkylation of ditetrazole I afforded a mixture of isomers, N 2 -isomer II prevailing.…”

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confidence: 99%

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Polynuclear tetrazole-containing amino acid analogs

et al. 2004

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New analogs of (D,L)-phenylalanine containing tetrazole rings were synthesized. The acidity constants of (D,L)-phenylalanine and (D,L)-tryptophane derivatives containing a tetrazole ring with no substituent on N 1 (pK a = 3.0-3.1) and of the corresponding carboxylic acids (pK a = 2.9-3.3) in aqueous methanol were determined by potentiometric titration.SiX 3 = SiCl n (N 3 ) 3 -n , n = 0-3.Tetrazole-containing analogs of amino acids and peptides are important for the development of modern therapeutic agents due to their resistance to enzymatic cleavage and hydrolysis and the possibility for improving bioavailability and bioselectivity. A combination of such properties is favorable from the viewpoint of pharmacology, thus making these compounds attractive targets of organic synthesis. For example, Zabrocki et al. [1] proposed to modify peptides or particular amino acids with tetrazole fragments to obtain some peptidomimetics with a cis-blocked peptide bond. For this purpose, a secondary amine is generally treated with PCl 5 in the presence of quinoline, and intermediate imidoyl chloride is brought into reaction with a solution of hydrazoic acid [1, 2]. An alternative way of peptide bond modification with a tetrazole fragment involves the system PPh 3 -DEAD-TMSN 3 [3]. It was also shown [4] that reactions of N-substituted carboxylic acid amides with trifluoromethanesulfonic anhydride (Tf 2 O) and sodium azide give the corresponding 1,5-disubstituted tetrazoles [4].El-Ahl et al. [5] recently proposed a procedure for the synthesis of tetrazoles from carboxamides using the system tetrachlorosilane-sodium azide. A probable mechanism of this process is shown in Scheme 1. The system SiCl 4 -NaN 3 ensures preparation of both 1,5-disubstituted [6] and 1-unsubstituted tetrazoles [5,6], and it can be applied to various substrates, amino acids among these. Following this procedure, tetrazole-containing analogs of (D,L)-phenylalanine, (D,L)-leucine [7], and (D,L)-tryptophane [8] were synthesized.We have extended the above approach to the synthesis of structures containing both two and three tetrazole rings. As starting compound we used previously synthesized ditetrazole I [7]. It was treated with chloroacetamide in the presence of triethylamine to obtain tetrazolylacetamide II, and reaction of the latter with the system tetrachlorosilane-sodium azide gave compound III containing three differently substituted tetrazole rings. By alkaline hydrolysis of II we obtained tetrazolylacetic acid IV (Scheme 2). The syntheses were performed according to the procedures

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confidence: 99%

“…Following this procedure, tetrazole-containing analogs of (D,L)-phenylalanine, (D,L)-leucine [7], and (D,L)-tryptophane [8] were synthesized.…”

mentioning

confidence: 99%

mentioning

confidence: 99%