1,3-Dipolar cycloaddition of 2-diazopropane to imidazo[1,2-b]pyridazine derivatives. The synthesis of imidazo[1,2-b]pyrazolo[4,3-d]pyridazines derivatives of a novel heterocyclic system

New pyrrolo[1,2-b]pyridazine derivatives 8a-f were synthesized by 1,3-dipolar cycloaddition reaction between mesoionic 1,3-oxazolo[3,2-b]pyridazinium-2-oxides and diethyl or diisopropyl acetylenedicarboxylate as alkyne dipolarophiles. The structures of the new compounds were assigned by elemental analysis and NMR spectroscopy.

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Synthesis of Novel 1,2,3-Triazole Derivatives of Isocoumarins and 3,4-Dihydroisocoumarin with Potential Antiplasmodial Activity In Vitro

Medicinal Chemistry ◽

10.2174/1573406416666200602161047 ◽

2020 ◽

Vol 16 ◽

Author(s):

Lucas da Silva Santos ◽

Matheus Fillipe Langanke de Carvalho ◽

Ana Claudia de Souza Pinto ◽

Amanda Luisa da Fonseca ◽

Julio César Dias Lopes ◽

...

Keyword(s):

Triazole Ring ◽

Antiplasmodial Activity ◽

World Health ◽

Dipolar Cycloaddition ◽

Terminal Alkynes ◽

The World ◽

Ic50 Values ◽

Derivatives Of ◽

Active Substances

Background: Malaria greatly affects the world health, having caused more than 228 million cases only in 2018. The emergence of drug resistance is one of the main problems in its treatment, demonstrating the urge for the development of new antimalarial drugs. Objective: Synthesis and in vitro antiplasmodial evaluation of triazole compounds derived from isocoumarins and a 3,4- dihydroisocoumarin. Method: The compounds were synthesized in 4 to 6-step reactions with the formation of the triazole ring via the Copper(I)-catalyzed 1,3-dipolar cycloaddition between isocoumarin or 3,4-dihydroisocoumarin azides and terminal alkynes. This key reaction provided compounds with an unprecedented connection of isocoumarin or 3,4-dihydroisocoumarin and the 1,2,3-triazole ring. The products were tested for their antiplasmodial activity against a Plasmodium falciparum chloroquine resistant and sensitive strains (W2 and 3D7, respectively). Results: Thirty-one substances were efficiently obtained by the proposed routes with an overall yield of 25-53%. The active substances in the antiplasmodial test displayed IC50 values ranging from 0.68-2.89 μM and 0.85-2.07 μM against W2 and 3D7 strains, respectively.

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1,3-dipolar cycloaddition in the synthesis of glycoconjugates of natural chlorins and bacteriochlorins

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424609000425 ◽

2009 ◽

Vol 13 (03) ◽

pp. 336-345 ◽

Cited By ~ 16

Author(s):

Mikhail A. Grin ◽

Ivan S. Lonin ◽

Anna A. Lakhina ◽

Elena S. Ol'shanskaya ◽

Alexey I. Makarov ◽

...

Keyword(s):

Triple Bond ◽

Tautomeric Form ◽

Click Reaction ◽

Copper Cation ◽

Water Soluble ◽

Dipolar Cycloaddition ◽

Nmr Studies ◽

Metal Free ◽

Cu Complex ◽

Derivatives Of

Glucose-, galactose- and lactose-containing photosensitizers based on derivatives of chlorophyll a and bacteriochlorophyll a were synthesized with the use of [3+2] cycloaddition between sugar azides and triple bond derivatives of chlorins and bacteriochlorins. Unlike bacteriochlorin cycloimide, chlorin was detected to form a Cu -complex during the click reaction. An approach to the synthesis of metal-free glycosylated chlorins was developed with the use of "protection" by Zn 2+ cation and subsequent demetalation. It is based on the action of alkynyl chlorin e6 derivative Zn -complex, which is resistant to the substitution by copper cation. Bacteriochlorin p cycloimide conjugate with per-acetylated β-D-lactose was obtained and shown to become water-soluble after unblocking of the lactose hydroxy functions. NMR studies allowed for the elucidation of structure, tautomeric form and conformation of the obtained compounds.

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