Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

• Vladislav A. Budevich,
• Sergei V. Voitekhovich,
• Alexander V. Zuraev,
• Vadim E. Matulis,
• Vitaly E. Matulis,
• Alexander S. Lyakhov,
• Ludmila S. Ivashkevich and
• Oleg A. Ivashkevich

Beilstein J. Org. Chem. 2021, 17, 385–395, doi:10.3762/bjoc.17.34

• , Leningradskaya 14, 220006 Minsk, Republic of Belarus Inorganic chemistry department, Faculty of Chemistry, Belarusian State University, Nezalezhnastsi avenue 4, 220050 Minsk, Republic of Belarus 10.3762/bjoc.17.34 Abstract Tetrazolium-5-aminides have been prepared by the tert-butylation of 5-aminotetrazole and

• : aminotetrazoles; DFT; mesoionic compounds; UV–vis spectra; X-ray analysis; Introduction 5-Aminotetrazoles are one of the most available and valuable tetrazole derivatives. So, due to the thermal stability and high nitrogen content the parent 5-aminotetrazole (1, Figure 1) is of practical interest as a gas

• attractive as environmentally friendly pyrotechnics [4], insensitive high-energy materials [5][6][7], and promising energetic ionic liquids [8][9][10]. The most interesting and less examined 5-aminotetrazole derivatives are tetrazolium-5-aminides, which can be depicted as 4 by analogy with other mesoionic

Microwave-assisted efficient one-pot synthesis of N²-(tetrazol-5-yl)-6-aryl/heteroaryl-5,6-dihydro-1,3,5-triazine-2,4-diamines

• Moustafa Sherief Moustafa,
• Ramadan Ahmed Mekheimer,
• Saleh Mohammed Al-Mousawi,
• Mohamed Abd-Elmonem,
• Hesham El-Zorba,
• Afaf Mohamed Abdel Hameed,
• Tahany Mahmoud Mohamed and
• Kamal Usef Sadek

Beilstein J. Org. Chem. 2020, 16, 1706–1712, doi:10.3762/bjoc.16.142

• 5-aminotetrazole (3) in pyridine under controlled microwave heating (Scheme 2). Results and Discussion With the initial aim of optimizing the reaction conditions, we began our study by reacting equimolar amounts of cyanamide 1, aromatic aldehydes 2, and 5-aminotetrazole (3) in pyridine and the

• participated in the reaction course and the yield was increased to 92% when the molar ratio of the reactants 1, 2, and 3 was set at 2:1:1. We next surveyed a structurally diverse group of aromatic aldehydes 2 with cyanamide 1 and 5-aminotetrazole (3) under the same experimental conditions and the results are

• unequivocally supported by single-crystal X-ray diffraction (Figure 1 and Table 2). A plausible mechanism for the formation of products 4 is postulated in Scheme 3. The dimerization of cyanamide 1 in basic medium to cyanoguanidine 5 and subsequent reaction with 5-aminotetrazole (3) yielded tetrazolylbiguanidine

In water multicomponent synthesis of low-molecular-mass 4,7-dihydrotetrazolo[1,5-a]pyrimidines

• Irina G. Tkachenko,
• Sergey A. Komykhov,
• Vladimir I. Musatov,
• Svitlana V. Shishkina,
• Viktoriya V. Dyakonenko,
• Vladimir N. Shvets,
• Mikhail V. Diachkov,
• Valentyn A. Chebanov and
• Sergey M. Desenko

Beilstein J. Org. Chem. 2019, 15, 2390–2397, doi:10.3762/bjoc.15.231

• , Ukraine Bar-Ilan University Ramat Gan, 5290002, Israel 10.3762/bjoc.15.231 Abstract The three-component reaction of 5-aminotetrazole with aliphatic aldehydes (formaldehyde, acetaldehyde) and acetoacetic ester derivatives in water under microwave irradiation leads to the selective formation of 4,7

• was assayed with 1,1-diphenyl-2-picrylhydrazyl. Keywords: 5-aminotetrazole; antioxidant activity; 1,3-dicarbonyl compounds; multicomponent synthesis; tetrazolo[1,5-a]pyrimidines; Introduction Tetrazolo[1,5-a]pyrimidines and their partially hydrogenated derivatives are known for their interesting

• -withdrawing properties of the tetrazole ring, which makes them useful for studying various theoretical issues, e.g., tautomerism [5], intramolecular transformations [6], etc. There are several approaches to the synthesis of 4,7-dihydrotetrazolo[1,5-a]pyrimidines. Two of them make use of 5-aminotetrazole as a

¹⁵N-Labelling and structure determination of adamantylated azolo-azines in solution

• Sergey L. Deev,
• Alexander S. Paramonov,
• Tatyana S. Shestakova,
• Igor A. Khalymbadzha,
• Oleg N. Chupakhin,
• Julia O. Subbotina,
• Oleg S. Eltsov,
• Pavel A. Slepukhin,
• Vladimir L. Rusinov,
• Alexander S. Arseniev and
• Zakhar O. Shenkarev

Beilstein J. Org. Chem. 2017, 13, 2535–2548, doi:10.3762/bjoc.13.250

• this approach for the syntheses of 15N-labelled tetrazolo[1,5-b][1,2,4]triazines and tetrazolo[1,5-a]pyrimidines [25] starting from 15N-labelled 5-aminotetrazole. However, due to proton tautomerism, the use of single-labelled [2-15N]-5-aminotetrazole led to the formation of isotopomer mixtures, which

• complicated the subsequent NMR analysis. Meanwhile, the application of [2,3-15N2]-5-aminotetrazole 7-15N2 provided the single double-labelled products in the tetrazolo[1,5-a]pyrimidine series [33]. Thus, in the current work, [2,3-15N2]-5-aminotetrazole 7-15N2 (98% enrichment for each of the labelled 15N atoms

• ) was used to incorporate isotopic labels in the tetrazolo[1,5-b][1,2,4]triazine core (Scheme 1). The interaction of diazonium salt 8-15N2 derived from [2,3-15N2]-5-aminotetrazole 7-15N2 with ethyl α-formylphenylacetate (9) yielded compound 10-15N2. It was expected that the cyclization of 10-15N2 would

Synthesis, effect of substituents on the regiochemistry and equilibrium studies of tetrazolo[1,5-a]pyrimidine/2-azidopyrimidines

• Elisandra Scapin,
• Paulo R. S. Salbego,
• Caroline R. Bender,
• Alexandre R. Meyer,
• Anderson B. Pagliari,
• Tainára Orlando,
• Geórgia C. Zimmer,
• Clarissa P. Frizzo,
• Helio G. Bonacorso,
• Nilo Zanatta and
• Marcos A. P. Martins

Beilstein J. Org. Chem. 2017, 13, 2396–2407, doi:10.3762/bjoc.13.237

• cyclocondensation reaction [CCC + NCN] was developed. The NCN corresponds to 5-aminotetrazole and CCC to β-enaminone. Two distinct products were observed in accordance with the β-enaminone substituent. When observed in solution, the compounds can be divided into two groups: (a) precursor compounds with R = CF3 or

• formed from 5-aminotetrazole, such as 1,3-binucleophile synthons, have not been sufficiently discussed [17]. Today, several existing methods are known to have several disadvantages, including long reaction time, the use of harmful solvents, and multistep synthesis [18][19]. Moreover, researchers in the

• -dimethylamino vinyl ketones, and the NCN block is 5-aminotetrazole. Results and Discussion Synthesis of tetrazolo[1,5-a]pyrimidines The β-dimethylamino vinyl ketones (β-enaminones) were synthesized using methodologies previously described by our research group [31]. In order to achieve better reaction

The reactions of 2-ethoxymethylidene-3-oxo esters and their analogues with 5-aminotetrazole as a way to novel azaheterocycles

• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess and
• Viktor I. Saloutin

Beilstein J. Org. Chem. 2015, 11, 385–391, doi:10.3762/bjoc.11.44

• -oxo esters and their analogues with 5-aminotetrazole is an efficient synthetic approach to novel azaheterocycles. 2-Ethoxymethylidene-3-oxo esters bearing alkyl substituents react with 5-aminotetrazole to form ethyl 2-azido-4-alkylpyrimidine-5-carboxylates which are capable of subsequent nucleophilic

• -benzoyl-3-ethoxyprop-2-enoate reacted with 5-aminotetrazole by two reaction routes to form ethyl 2-benzoyl-3-(1H-tetrazol-5-ylamino)prop-2-enoate and ethyl 7-(1-ethoxy-1,3-dioxo-3-phenylpropan-2-yl)-5-phenyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate. Keywords: 5-aminotetrazole; cyclisation

• -oxo esters and their analogues with 5-aminotetrazole (5-AT), although these reactions can be used to generate functionalized tetrazolo[1,5-a]pyrimidines. Derivatives of these heterocycles are promising objects for biological testing, because substances possessing apoptotic and antitumor [13

The unexpected influence of aryl substituents in N-aryl-3-oxobutanamides on the behavior of their multicomponent reactions with 5-amino-3-methylisoxazole and salicylaldehyde

• Volodymyr V. Tkachenko,
• Elena A. Muravyova,
• Sergey M. Desenko,
• Oleg V. Shishkin,
• Svetlana V. Shishkina,
• Dmytro O. Sysoiev,
• Thomas J. J. Müller and
• Valentin A. Chebanov

Beilstein J. Org. Chem. 2014, 10, 3019–3030, doi:10.3762/bjoc.10.320

• spectrum of biological activity [5][6], which led to choose acetoacetamides as perspective methylene-active compounds for further studies of multicomponent reactions. The interactions of 3-oxobutanamides with aldehydes and a number of aminoazoles, namely 3-amino-1,2,4-triazoles [7][8][9][10][11], 5

• -aminotetrazole [9], 5-aminopyrazoles [11], and 5-amino-1,2,3-triazole [12] have previously been investigated. In some cases when the reaction could proceed in two alternative pathways the conditions enabling to control the interaction direction were determined, which made it possible to obtain the desired