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Medicinal Chemistry

Editor-in-Chief

ISSN (Print): 1573-4064
ISSN (Online): 1875-6638

Research Article

Zinc 1,2,4-triazolo[1,5-a]pyrimidine Complexes: Synthesis, Structural Characterization and their Effect Against Chagas Disease

Author(s): José M. Méndez-Arriaga*, Erika Rubio-Mirallas, Miguel Quirós and Manuel Sánchez-Moreno

Volume 18, Issue 4, 2022

Published on: 12 August, 2021

Page: [444 - 451] Pages: 8

DOI: 10.2174/1573406417666210812162500

Price: $65

Abstract

Background: The World Health Organization catalogues illnesses such as Chagas disease as neglected diseases, due to the low investment in new drugs to fight them. The search for novel and non-side effects anti-parasitic compounds is one of the urgent needs of the Third World. The use of triazolopyrimidines and their metal complexes have demonstrated hopeful results in this field.

Objective: This work studies the antiparasitic efficacy against Trypanosoma cruzi strains of a series of zinc triazolopyrimidine complexes.

Methods: A series of Zn complexes has been synthesized by the reaction between the triazolopyrimidine derivatives 7-amino-1,2,4-triazolo[1,5-a]pyrimidine (7atp) and 5,7-dimethyl-1,2,4-triazolo[1,5- a]pyrimidine (dmtp) with Zn(SO4) · 7H2O, ZnCl2, and Zn(NO3)2 · 6H2O salts. The complexes have been analyzed by spectroscopic and thermal assays and X-ray diffraction methods have been used to dilucidate the crystalline structure of one of them. The antiparasitic efficacy was tested in vitro against Trypanosoma cruzi to compare the trypanocidal effect of different ligands and counteranions to fight Chagas disease.

Results: The efficacy of these compounds against Trypanosoma cruzi has also been tested to compare the influence of different ligands and counteranions on the trypanocidal effect against Chagas disease.

Conclusion: Antiproliferative tests corroborate the synergistic trypanocidal effect of the triazolopyrimidine coordination complexes.

Keywords: Triazolopyrimidine ligands, metal complexes, crystallography, parasitology, Chagas disease, zinc complexes.

Graphical Abstract

[1]
Bulow, C.; Haas, K. Synthetische versuche zur darstellung von derivaten des heterokondensierten, heterocyclischen 1.3‐Triazo‐7.0′‐pyrimidins. Chem. Ber., 1909, 42, 4638-4644.
[http://dx.doi.org/10.1002/cber.19090420468]
[2]
Birr. Z. Wiss. Photogr. Photophys. Photochem., 1952, 47, 2-27.
[3]
Fischer, G. Recent progress in 1,2,4-triazolo[1,5-a]pyrimidine chemistry. Adv. Heterocycl. Chem., 2008, 95, 143-219.
[http://dx.doi.org/10.1016/S0065-2725(07)95003-5]
[4]
Singh, P.K.; Choudhary, S.; Kashyap, A.; Verma, H.; Kapil, S.; Kumar, M.; Arora, M.; Silakari, O. An exhaustive compilation on chemistry of triazolopyrimidine: A journey through decades. Bioorg. Chem., 2019, 88102919
[http://dx.doi.org/10.1016/j.bioorg.2019.102919] [PMID: 31026721]
[5]
Maldonado, C.R.; Quirós, M.; Salas, J.M. 1,2,4-triazolo[1,5-a]pyrimidin-3-ium chloride. Acta Crystallogr. Sect. E Struct. Rep. Online, 2007, 63(3), o1509-o1510.
[http://dx.doi.org/10.1107/S1600536807008641]
[6]
Odabasoglu, M.; Büyükgüngör, O. 5,7-dimethyl-1,2,4-triazolo[1,5- a ]pyrimidine. Acta Crystallogr., 2002, 62, o1310-o1311.
[7]
Caballero, A.B.; Rodríguez-Diéguez, A.; Vidal, I.; Dobado, J.A.; Castillo, Ó.; Lezama, L.; Salas, J.M. Insights on the binding ability of a new adenine analog: 7-amine-1,2,4-triazolo[1,5-a]pyrimidine. Synthesis and magnetic study of the first copper(II) complexes. Dalton Trans., 2012, 41(6), 1755-1764.
[http://dx.doi.org/10.1039/C1DT11385B] [PMID: 22159299]
[8]
Abul Haj, M.; Salas, J.M.; Quirós, M.; Molina, J.; Faure, R. 5-oxo and 7-oxo derivatives of [1,2,4]triazolo-[1,5-a]pyrimidine: characterization and theoretical study. J. Mol. Struct., 2000, 519, 165-172.
[http://dx.doi.org/10.1016/S0022-2860(99)00303-8]
[9]
Navarro, J.A.R.; Romero, M.A.; Salas, J.M.; Faure, R.; Solans, X. Polymeric silver(I) complexes of the multinucleating ligand 4,7-dihydro-5-methyl-7-oxo(1,2,4)triazolo(1,5-alpha)pyrimidine -analogous hydrogen-bonded structures in the crystal and vapor-phases of the ligand. J. Chem. Soc., Dalton Trans., 1997, 2321-2326.
[http://dx.doi.org/10.1039/a700888k]
[10]
Méndez-Arriaga, J.M.; Esteban-Parra, G.M.; Juárez, M.J.; Rodríguez-Diéguez, A.; Sánchez-Moreno, M.; Isac-García, J.; Salas, J.M. Antiparasitic activity against trypanosomatid diseases and novel metal complexes derived from the first time characterized 5-phenyl-1,2,4-triazolo[1,5-a]pyrimidi-7(4H)-one. J. Inorg. Biochem., 2017, 175, 217-224.
[http://dx.doi.org/10.1016/j.jinorgbio.2017.07.026] [PMID: 28780409]
[11]
Barbosa, M.I.F.; Corrêa, R.S.; de Oliveira, K.M.; Rodrigues, C.; Ellena, J.; Nascimento, O.R.; Rocha, V.P.C.; Nonato, F.R.; Macedo, T.S.; Barbosa-Filho, J.M.; Soares, M.B.; Batista, A.A. Antiparasitic activities of novel ruthenium/lapachol complexes. J. Inorg. Biochem., 2014, 136, 33-39.
[http://dx.doi.org/10.1016/j.jinorgbio.2014.03.009] [PMID: 24727183]
[12]
Rodríguez Arce, E.; Machado, I.; Rodríguez, B.; Lapier, M.; Zúñiga, M.C.; Maya, J.D.; Olea Azar, C.; Otero, L.; Gambino, D. Rhenium(I) tricarbonyl compounds of bioactive thiosemicarbazones: Synthesis, characterization and activity against Trypanosoma cruzi. J. Inorg. Biochem., 2017, 170, 125-133.
[http://dx.doi.org/10.1016/j.jinorgbio.2017.01.011] [PMID: 28237731]
[13]
Fandzloch, M.; Arriaga, J.M.M.; Sánchez-Moreno, M.; Wojtczak, A.; Jezierska, J.; Sitkowski, J.; Wiśniewska, J.; Salas, J.M.; Łakomska, I. Strategies for overcoming tropical disease by ruthenium complexes with purine analog: Application against Leishmania spp. and Trypanosoma cruzi. J. Inorg. Biochem., 2017, 176, 144-155.
[http://dx.doi.org/10.1016/j.jinorgbio.2017.08.018] [PMID: 28910663]
[14]
Esteban‐Parra, G.M.; Moscoso, I. Cepeda, J.; García, J.A.; Sánchez‐Moreno, S.; Rodríguez‐Diéguez, A.; Quirós, M. Lanthanide(III) based complexes containing 5,7‐dimethyl‐1,2,4‐triazolo[1,5‐a]pyrimidine as long‐lived photoluminescent antiparasitic agents. Eur. J. Inorg. Chem., 2020, 2020(3), 308-317.
[http://dx.doi.org/10.1002/ejic.201901119]
[15]
Miserachs, H.G.; Cipriani, M.; Grau, J.; Vilaseca, M.; Lorenzo, J.; Medeiros, A.; Comini, M.A.; Gambino, D.; Otero, L.; Moreno, V. Antitumor and antiparasitic activity of novel ruthenium compounds with polycyclic aromatic ligands. J. Inorg. Biochem., 2015, 150, 38-47.
[http://dx.doi.org/10.1016/j.jinorgbio.2015.06.007] [PMID: 26079954]
[16]
Hassan, G.S.; El-Sherbeny, M.A.; El-Ashmawy, M.B.; Bayomi, S.M.; Maarouf, A.R.; Badria, F.A. Synthesis and antitumor testing of certain new fused triazolopyrimidine and triazoloquinazoline derivatives. Arab. J. Chem., 2017, 10, S1345-S1355.
[http://dx.doi.org/10.1016/j.arabjc.2013.04.002]
[17]
Rice, D.R.; Vacchina, P.; Norris-Mullins, B.; Morales, M.A.; Smith, B.D. Zinc(II)-dipicolylamine coordination complexes as targeting and chemotherapeutic agents for Leishmania major. Antimicrob. Agents Chemother., 2016, 60(5), 2932-2940.
[http://dx.doi.org/10.1128/AAC.00410-16] [PMID: 26926632]
[18]
Rodríguez Arce, E.; Mosquillo, M.F.; Pérez-Díaz, L.; Echeverría, G.A.; Piro, O.E.; Merlino, A.; Coitiño, E.L.; Maríngolo Ribeiro, C.; Leite, C.Q.F.; Pavan, F.R.; Otero, L.; Gambino, D. Aromatic amine N-oxide organometallic compounds: searching for prospective agents against infectious diseases. Dalton Trans., 2015, 44(32), 14453-14464.
[http://dx.doi.org/10.1039/C5DT00557D] [PMID: 26203896]
[19]
Gambino, D. Potentiality of vanadium compounds as anti-parasitic agents. Coord. Chem. Rev., 2011, 255(19), 2193-2203.
[http://dx.doi.org/10.1016/j.ccr.2010.12.028]
[20]
Łakomska, I.; Fandzloch, M. Application of 1,2,4-triazolo[1,5-a]pyrimidines for the design of coordination compounds with interesting structures and new biological properties. Coord. Chem. Rev., 2016, 327-328, 221-241.
[http://dx.doi.org/10.1016/j.ccr.2016.04.014]
[21]
Salas, J.M.; Romero, M.A.; Sánchez, M.P.; Quirós, M. Metal complexes of [1,2,4]triazolo-[1,5-a]pyrimidine derivatives. Coord. Chem. Rev., 1999, 195, 1119-1142.
[http://dx.doi.org/10.1016/S0010-8545(99)00004-1]
[22]
Salas, J.M.; Caballero, A.B.; Esteban-Parra, G.M.; Méndez-Arriaga, J.M. Leishmanicidal and trypanocidal activity of metal complexes with 1,2,4-triazolo[1,5-a]pyrimidines: insights on their therapeutic potential against leishmaniasis and chagas disease. Curr. Med. Chem., 2017, 24(25), 2796-2806.
[http://dx.doi.org/10.2174/0929867324666170516122024] [PMID: 28521698]
[23]
Caballero, A.B.; Salas, J.M.; Sánchez Moreno, M. Metal Based Therapeutics for Leishmaniasis in: Leishmaniasis - Trends in Epidemiology, Diagnosis and Treatment, David M. Claborn, Ed.; Chapter 20, 2014.
[24]
Méndez-Arriaga, J.M.; Rodríguez-Diéguez, A.; Sánchez-Moreno, M. In vitro leishmanicidal activity of copper (II) 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine complex and analogous transition metal series. Polyhedron, 2020, 176114272
[http://dx.doi.org/10.1016/j.poly.2019.114272]
[25]
Caballero, A.B.; Maclaren, J.K.; Rodríguez-Diéguez, A.; Vidal, I.; Dobado, J.A.; Salas, J.M.; Janiak, C. Dinuclear silver(I) complexes for the design of metal-ligand networks based on triazolopyrimidines. Dalton Trans., 2011, 40(44), 11845-11855.
[http://dx.doi.org/10.1039/c1dt10603a] [PMID: 21971399]
[26]
Astakhov, A.V.; Sokolov, A.N.; Pyatakov, D.A.; Shishkina, S.V.; Shishkin, O.V.; Chernyshev, V.M. Reactivity of 2-amino[1,2,4]triazolo[1,5-a]-pyrimidines with various saturation of the pyrimidine ring towards electrophiles. Chem. Heterocycl. Compd., 2016, 51, 1039-1047.
[http://dx.doi.org/10.1007/s10593-016-1816-8]
[27]
Esteban-Parra, G.M.; Méndez-Arriaga, J.M.; Rodríguez-Diéguez, A.; Quirós, M.; Salas, J.M.; Sánchez-Moreno, M. High antiparasitic activity of silver complexes of 5,7-dimethyl-1,2,4-triazolo[1,5 a]pyrimidine. J. Inorg. Biochem., 2019, 201110810
[http://dx.doi.org/10.1016/j.jinorgbio.2019.110810] [PMID: 31493678]
[28]
Wang, H.; Lee, M.; Peng, Z.; Blázquez, B.; Lastochkin, E.; Kumarasiri, M.; Bouley, R.; Chang, M.; Mobashery, S. Synthesis and evaluation of 1,2,4-triazolo[1,5-a]pyrimidines as antibacterial agents against Enterococcus faecium. J. Med. Chem., 2015, 58(10), 4194-4203.
[http://dx.doi.org/10.1021/jm501831g] [PMID: 25923368]
[29]
Boutaleb-Charki, S.; Marín, C.; Maldonado, C.R.; Rosales, M.J.; Urbano, J.; Guitierrez-Sánchez, R.; Quirós, M.; Salas, J.M.; Sánchez-Moreno, M. Copper (II) complexes of [1,2,4]triazolo [1,5-a]pyrimidine derivatives as potential anti-parasitic agents. Drug Metab. Lett., 2009, 3(1), 35-44.
[http://dx.doi.org/10.2174/187231209787176317] [PMID: 19356115]
[30]
Méndez-Arriaga, J.M.; Oyarzabal, I.; Escolano, G.; Rodríguez-Diéguez, A.; Sánchez-Moreno, M.; Salas, J.M. In vitro leishmanicidal and trypanocidal evaluation and magnetic properties of 7-amino-1,2,4-triazolo[1,5-a]pyrimidine Cu(II) complexes. J. Inorg. Biochem., 2018, 180, 26-32.
[http://dx.doi.org/10.1016/j.jinorgbio.2017.11.027] [PMID: 29227923]
[31]
Méndez-Arriaga, J.M.; Oyarzabal, I.; Martín-Montes, Á.; García-Rodríguez, J.; Quirós, M.; Sánchez-Moreno, M. First example of antiparasitic activity influenced by thermochromism: leishmanicidal evaluation of 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine metal complexes. Med. Chem., 2020, 16(3), 422-430.
[http://dx.doi.org/10.2174/1573406415666190401120607] [PMID: 30931864]
[32]
Fandzloch, M.; Wojtczak, A.; Wis̈niewska, J.; Stefańczak, K.; Salas, J.M.; Łakomska, I. Ruthenium(III) complexes with monodentate 5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7(4H)-one: Structural characterization, interaction with DNA and proteins. Inorg. Chim. Acta, 2016, 443, 170-178.
[http://dx.doi.org/10.1016/j.ica.2015.12.036]
[33]
Weiss, L.M.; Tanowitz, H.B.; Kirchhoff, L.V. Epidemiology of American Trypanosomiasis (Chagas Disease) In: Chagas Disease, Part A., Chapter 1. Adv. Parasitol., 2011, 75, 1-18.
[http://dx.doi.org/10.1016/B978-0-12-385863-4.00001-0]
[34]
WHO Control of Chagas disease. W.H.O. Tech. Rep. Ser., 2002, 905, 24-28.
[35]
Gambino, D.; Otero, L. Perspectives on what ruthenium-based compounds could offer in the development of potential antiparasitic drugs. Inorg. Chim. Acta, 2012, 393, 103-114.
[http://dx.doi.org/10.1016/j.ica.2012.05.028]
[36]
Clayton, J. Chagas disease: pushing through the pipeline. Nature, 2010, 465(7301), S12-S15.
[http://dx.doi.org/10.1038/nature09224] [PMID: 20571548]
[37]
Hotez, P.J.; Molyneux, D.H.; Fenwick, A.; Kumaresan, J.; Sachs, S.E.; Sachs, J.D.; Savioli, L. Control of neglected tropical diseases. N. Engl. J. Med., 2007, 357(10), 1018-1027.
[http://dx.doi.org/10.1056/NEJMra064142] [PMID: 17804846]
[38]
Stuart, K.; Brun, R.; Croft, S.; Fairlamb, A.; Gürtler, R.E.; McKerrow, J.; Reed, S.; Tarleton, R. Kinetoplastids: related protozoan pathogens, different diseases. J. Clin. Invest., 2008, 118(4), 1301-1310.
[http://dx.doi.org/10.1172/JCI33945] [PMID: 18382742]
[39]
Croft, S.L.; Barrett, M.P.; Urbina, J.A. Chemotherapy of trypanosomiases and leishmaniasis. Trends Parasitol., 2005, 21(11), 508-512.
[http://dx.doi.org/10.1016/j.pt.2005.08.026] [PMID: 16150644]
[40]
Delespaux, V.; de Koning, H.P. Drugs and drug resistance in African trypanosomiasis. Drug Resist. Updat., 2007, 10(1-2), 30-50.
[http://dx.doi.org/10.1016/j.drup.2007.02.004] [PMID: 17409013]
[41]
Urbina, J.A. Specific chemotherapy of Chagas disease: relevance, current limitations and new approaches. Acta Trop., 2010, 115(1-2), 55-68.
[http://dx.doi.org/10.1016/j.actatropica.2009.10.023] [PMID: 19900395]
[42]
Berman, J.D.; Gallalee, J.V.; Best, J.M. Sodium stibogluconate (Pentostam) inhibition of glucose catabolism via the glycolytic pathway, and fatty acid beta-oxidation in Leishmania mexicana amastigotes. Biochem. Pharmacol., 1987, 36(2), 197-201.
[http://dx.doi.org/10.1016/0006-2952(87)90689-7] [PMID: 3028425]
[43]
Baneth, G.; Shaw, S.E. Chemotherapy of canine Leishmaniosis. Vet. Parasitol., 2002, 106(4), 315-324.
[http://dx.doi.org/10.1016/S0304-4017(02)00115-2] [PMID: 12079737]
[44]
Momeni, A.Z.; Reiszadae, M.R.; Aminjavaheri, M. Treatment of cutaneous leishmaniasis with a combination of allopurinol and low-dose meglumine antimoniate. Int. J. Dermatol., 2002, 41(7), 441-443.
[http://dx.doi.org/10.1046/j.1365-4362.2002.01527.x] [PMID: 12121563]
[45]
Palumbo, E. Current treatment for cutaneous leishmaniasis: a review. Am. J. Ther., 2009, 16(2), 178-182.
[http://dx.doi.org/10.1097/MJT.0b013e3181822e90] [PMID: 19300044]
[46]
Natera, S.; Machuca, C.; Padrón-Nieves, M.; Romero, A.; Díaz, E.; Ponte-Sucre, A. Leishmania spp.: proficiency of drug-resistant parasites. Int. J. Antimicrob. Agents, 2007, 29(6), 637-642.
[http://dx.doi.org/10.1016/j.ijantimicag.2007.01.004] [PMID: 17353113]
[47]
Croft, S.L.; Sundar, S.; Fairlamb, A.H. Drug resistance in leishmaniasis. Clin. Microbiol. Rev., 2006, 19(1), 111-126.
[http://dx.doi.org/10.1128/CMR.19.1.111-126.2006] [PMID: 16418526]
[48]
Magán, R.; Marín, C.; Rosales, M.J.; Barrera, M.A.; Salas, J.M.; Sánchez-Moreno, M. Activities of Pt(II) and Ru(III) triazole-pyrimidine complexes against Trypanosoma cruzi and T. brucei brucei. Pharmacology, 2004, 70(2), 83-90.
[http://dx.doi.org/10.1159/000074672] [PMID: 14685011]
[49]
Moreno-Viguri, E.; Jiménez-Montes, C.; Martín-Escolano, R.; Santivañez-Veliz, M.; Martín-Montes, A.; Azqueta, A.; Jiménez-López, M.; Zamora Ledesma, S.; Cirauqui, N.; López de Ceráin, A.; Marín, C.; Sánchez-Moreno, M.; Pérez-Silanes, S. In vitro and in vivo anti-Trypanosoma cruzi activity of new arylamine Mannich base-type derivatives. J. Med. Chem., 2016, 59(24), 10929-10945.
[http://dx.doi.org/10.1021/acs.jmedchem.6b00784] [PMID: 28002965]
[50]
Plano, D.; Baquedano, Y.; Moreno-Mateos, D.; Font, M.; Jiménez-Ruiz, A.; Palop, J.A.; Sanmartín, C. Selenocyanates and diselenides: a new class of potent antileishmanial agents. Eur. J. Med. Chem., 2011, 46(8), 3315-3323.
[http://dx.doi.org/10.1016/j.ejmech.2011.04.054] [PMID: 21571403]
[51]
Beltran-Hortelano, I.; Pérez-Silanes, S.; Galiano, S. Trypanothione reductase and superoxide dismutase as current drug targets for trypanosoma cruzi: an overview of compounds with activity against chagas disease. Curr. Med. Chem., 2017, 24(11), 1066-1138.
[http://dx.doi.org/10.2174/0929867323666161227094049] [PMID: 28025938]
[52]
Baquedano, Y.; Alcolea, V.; Toro, M.A.; Gutiérrez, K.J.; Nguewa, P.; Font, M.; Moreno, E.; Espuelas, S.; Jiménez-Ruiz, A.; Palop, J.A.; Plano, D.; Sanmartín, C. Novel heteroaryl selenocyanates and diselenides as potent antileishmanial agents. Antimicrob. Agents Chemother., 2016, 60(6), 3802-3812.
[http://dx.doi.org/10.1128/AAC.02529-15] [PMID: 27067328]
[53]
Morilla, M.J.; Romero, E.L. Nanomedicines against Chagas disease: an update on therapeutics, prophylaxis and diagnosis. Nanomedicine (Lond.), 2015, 10(3), 465-481.
[http://dx.doi.org/10.2217/nnm.14.185] [PMID: 25707979]
[54]
Téllez-Meneses, J.; Mejía-Jaramillo, A.M.; Triana-Chávez, O. Biological characterization of Trypanosoma cruzi stocks from domestic and sylvatic vectors in Sierra Nevada of Santa Marta, Colombia. Acta Trop., 2008, 108(1), 26-34.
[http://dx.doi.org/10.1016/j.actatropica.2008.08.006] [PMID: 18804443]
[55]
González, P.; Marín, C.; Rodríguez-González, I.; Hitos, A.B.; Rosales, M.J.; Reina, M.; Díaz, J.G.; González-Coloma, A.; Sánchez-Moreno, M. In vitro activity of C20-diterpenoid alkaloid derivatives in promastigotes and intracellular amastigotes of Leishmania infantum. Int. J. Antimicrob. Agents, 2005, 25(2), 136-141.
[http://dx.doi.org/10.1016/j.ijantimicag.2004.08.010] [PMID: 15664483]
[56]
Caballero, A.B.; Rodríguez-Diéguez, A.; Quirós, M.; Salas, J.M.; Huertas, Ó.; Ramírez-Macías, I.; Olmo, F.; Marín, C.; Chaves-Lemaur, G.; Gutierrez-Sánchez, R.; Sánchez-Moreno, M. Triazolopyrimidine compounds containing first-row transition metals and their activity against the neglected infectious Chagas disease and leishmaniasis. Eur. J. Med. Chem., 2014, 85, 526-534.
[http://dx.doi.org/10.1016/j.ejmech.2014.08.026] [PMID: 25127147]
[57]
Caballero, A.B.; Marín, C.; Ramírez-Macías, I.; Rodríguez-Diéguez, A.; Quirós, M.; Salas, J.M.; Sánchez-Moreno, M. Structural consequences of the introduction of 2,2′-bipyrimidine as auxiliary ligand in triazolopyrimidine-based transition metal complexes. in vitro antiparasitic activity. Polyhedron, 2012, 33, 137-144.
[http://dx.doi.org/10.1016/j.poly.2011.11.020]
[58]
2004. Bruker Apex2; Bruker AXS Inc.: Madison, Wisconsin, USA, 2004.
[59]
Sheldrick, G.M. SADABS, program for empirical adsorption correction, institute for inorganic chemistry; University of Gottingen: Germany, 1996.
[60]
Sheldrick, G.M. Crystal structure refinement with SHELXL. Acta Crystallogr. C Struct. Chem., 2015, 71(Pt 1), 3-8.
[http://dx.doi.org/10.1107/S2053229614024218] [PMID: 25567568]
[61]
Salas, J.M.; Romero, M.A.; Rahmani, A.; Faure, R. Dichlorobis(5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine-N3)zinc(II). Acta Crystallogr., 1994, C50, 510-512.
[62]
Salas, J.M.; Enrique, C.; Romero, M.A.; Takagi, K.; Aoki, K.; Miyashita, Y.; Suh, I. Synthesis and spectroscopic properties of metal complexes of 5, 7-dimethyl [1, 2, 4] triazolo [1, 5-a] pyrimidine. X-ray structure of the cobalt (II) and cadmium (II) complexes. Polyhedron, 1992, 11, 2903-2912.
[http://dx.doi.org/10.1016/S0277-5387(00)83594-9]
[63]
Maldonado, C.R.; Quirós, M.; Salas, J.M. One-dimensional zinc(II) polymers with 4,6-dimethyl-1,2,3-triazolo[4,5-d]pyrimidin-5,7-dionato built by bipyridyl-based ligands acting as spacers both in the first and in the second sphere. Inorg. Chim. Acta, 2011, 365(1), 371-376.
[http://dx.doi.org/10.1016/j.ica.2010.09.048]
[64]
De Souza, W.; Barrias, E.S. May the epimastigote form of Trypanosoma cruzi be infective? Acta Trop., 2020, 212105688
[http://dx.doi.org/10.1016/j.actatropica.2020.105688] [PMID: 32888934]

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