SYNTHESIS, CHARACTERISATION AND ANTIFUNGAL ACTIVITYOF SOME NEWLY SYNTHESISED POLYSUBSTITUTED PYRAZOLES

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (10) ◽  
pp. 23-29
Author(s):  
A. Kumar ◽  
◽  
C. P. Singh

A novel series of polysubstituted pyrazoles were synthesised by the cyclization of (α phenoxy/octyl) acetyl aryl hydrazones in presence of formic acid, by refluxing (α-phenoxy/octyl) acetic acid hydrazide and substituted aryl aldehyde, using C2H5OH as solvent. The newly synthesised compounds were characterised by IR, 1H NMR spectra and also screened for their promising biological activity i.e. antifungal activity.

Author(s):  
V. Khilya ◽  
O. Shablykina ◽  
M. Tsapko ◽  
S. Shilin ◽  
V. Moskvina ◽  
...  

The effect of the lanthanide shift reagent (LSR) – tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octa-dionate) of Europium – Eu(fod)3 – on 1H NMR spectra of functionalized 3-arylisocoumarins and 3-aryl-3,4-dihydroisocoumarins was investigated. Based on previous studies of LSR interactions with benzopyrones, it was expected that the main coordination centre for the Eu3+ would be the exocyclic Oxygen atom of the heterocycle, but the possibility of competition from aromatic substituent functional groups was also considered. By measuring lanthanide-induced shifts (LIS) of the proton signals of the molecules at different ratios of substrate and Eu(fod)3, specific LIS values were determined. Based on those, it was concluded that the main direction of LSR coordination with 3-(2-hydroxy-5-methylphenyl)-1Hisochromen-1-one, 3-(2-methoxy-5-methylphenyl)-1H-isochromen-1-one and 3-(2-methoxy-5-methylphenyl)isochroman-1-one is the exocyclic Oxygen atom of the heterocycle, because the maximum LIS were recorded for the H-8 atom of isochromone system of these derivatives. In the case of ethyl ester of [2-(4-(1-oxo-1H-isochromen-3-yl)phenoxy] acetic acid and methyl ester of [2-(4-(1-oxoisochroman-3-yl)phenoxy]acetic acid comparable LIS values were observed both for H-8 and for the methylene group of the hydroxyacetic acid fragment, therefore, in such molecules the coordination of the Eu3+ to the heterocycle or to the aliphatic ester group is almost equally probable. In spectrum of methyl ester of N-{[4-(1-oxo-1H-isochromen-3-yl)phenoxy]acetyl}valine and N-{[4-(1-oxoisochroman-3-yl)-phenoxy]acetyl}valine there are insignificant LIS of H-8; and the maximum LIS were observed for the signals of the protons neighboring the two carbonyl groups of hydroxyacetic acid and valine fragments. Thus, these compounds interact w


2021 ◽  
Vol 19 (1(73)) ◽  
pp. 10-15
Author(s):  
G. G. Yakovenko ◽  
M. V. Vovk

Aim. To develop convenient approaches to the synthesis of 6-amino- and 6-oxoimidazo[4,5-b]pyrazolo[3,4-e]pyridines as promising biologically active scaffolds.Results and discussion. It has been found that cyclocondensation of N-Boc-4-aminopyrazole-5-carbaldehydes with creatinine can be used as an effective method for obtaining 6-aminoimidazo[4,5-b]pyrazolo[3,4-e]pyridines previously unknown. For the synthesis of their 6-oxoanalogs, the reaction of 5-aminopyrazolo[4,3-b]pyridine-6-carboxylic acids used in a modifed Curtius rearrangement with diphenylphosphorylazide was successful. This method was implemented through the stage of the intermediate aminoisocyanates formation.Experimental part. The reaction of N-Boc-4-aminopyrazole-5-carbaldehydes with creatinine in the presence of pyrrolidine as a catalyst in refluxing acetic acid allowed to obtain 6-aminoimidazo[4,5-b]pirazolo[3,4-e]pyridines with the yields of 54 – 70 %. The structure of the compounds synthesized was proven by spectral measurements. In the 1H NMR spectra there were singlets of H-3 (7.63 – 7.88 ppm) and H-8 (7.87 – 8.26 ppm) protons, as well as broad singlets of the NH2 group in the range of 7.05 – 7.21 ppm. Heating of 5-aminopyrazolo[4,3-b]pyridine-6-carboxylic acids with triethylamine and diphenylphosphorylazide in dioxane for 6 hours gave 1-substituted imidazo[4,5-b]pyrazolo[3,4-е]pyridine-6(5Н)-ones with the yields of 67 – 80 %. The IR-spectra of the compounds synthesized were characterized by the absorption bands of the C=O (1705 – 1708 cm-1) and NH (3275 – 3281 cm-1) groups. 1H NMR-spectra were characterized by singlets of H-3 and H-8 protons in the intervals of 7.43 – 8.08 ppm and 7.92 – 8.32 ppm respectively, as well as by two broad singlets of NH-protons in the ranges of 10.90 – 11.12 ppm and 11.25 – 11.37 ppm.Conclusions. Effective approaches to the synthesis of new promising heterocyclic systems of 6-amino- and6-oxoimidazo[4,5-b]pirazolo[3,4-e]pyridines have been developed. Cyclocondensations of N-Boc-4-aminopyrazole-5-carbaldehydes with creatinine and 5-aminopyrazolo[4,3-b]pyridine-6-carboxylic acids with diphenylphosphorylazide have been proven to be convenient ways to obtain these compounds with good yields.Key words: N-Boc-4-aminopyrazole-5-carbaldehyde; creatinine; 5-aminopyrazolo[4,3-b]pyridine-6-carboxylic acid; diphenylphosphorylazide; 6-amino(oxo)imidazo[4,5-b]pyrazolo[3,4-e]pyridines;cyclocondensation


2013 ◽  
Vol 10 (3) ◽  
pp. 818-827
Author(s):  
Baghdad Science Journal

A series of new compounds including p-bromo methyl pheno acetate [2]. N-( aminocarbonyl)–p-bromo pheno acetamide [3] , N-( aminothioyl) -p-bromo phenoacetyl amide [4], N-[4-(p-di phenyl)-1,3-oxazol-2-yl]-p-bromopheno acetamide [5],N-[4-p-di phenyl]-1,3-thiazol-2-yl-p-bromo phenoacet amide [6], p-bromopheno acetic acid hydrazide [7] , 1-N-(p-bromo pheno acetyl)-1,2-dihydro-pyridazin-3,6- dione [8], 1-N-(p-bromo pheno acetyl)-1,2-dihydro-phthalazin-3,8- dione[ 9], 1-(p-bromo pheno acetyl)-3-methylpyrazol-5-one [10] and 1-(p-bromo phenol acetyl)- 3,5-dimethyl pyrazole [11] have been synthesized. The prepared compounds were characterized by m.p.,FT-IR and 1H-NMR spectroscopy. Also ,the biological activity was evaluated .


2020 ◽  
Vol 63 (9) ◽  
pp. 26-30
Author(s):  
Daria D. Rubtsova ◽  
◽  
Alexandra A. Bobyleva ◽  
Daria D. Lezhnina ◽  
Sofia V. Polikarpova ◽  
...  

In this work, pyrrolidin-2-ones and their derivatives are considered as a promising class of non-aromatic heterocyclic compounds. Their structure is found in the nuclei of many natural products and biologically active molecules. In pharmacy the possibility of introducing various substituents into the nucleus of pyrrolidin-2-ones is a great importance for the synthesis of new medicinal molecules with improved biological activity. Nowadays the synthesis of new active compounds by introducing various substituents at the C1-, C4- and C5-position of 3-hydroxy-3-pyrrolin-2-one has been little studied and it is of great interest to study the conditions of their synthesis, chemical properties and biological activity. In this research work the corresponding 5-aryl-3-hydroxy-1-(2-hydroxypropyl)-4-(furyl-2-carbonyl)-3-pyrrolin-2-ones and 5-aryl-3-hydroxy-1-(3-hydroxypropyl)-4-(furyl-2-carbonyl)-3-pyrrolin-2-ones were synthesized by the reaction of methyl ester of furyl-2-carbonylpyruvic acid with a mixture of aromatic aldehyde and 1-amino-2-hydroxypropane or 3-amino 1-hydroxypropane when heated in dioxane. The results of the study of the structure of the new synthesized compounds are presented. The structure was proved using 1H NMR spectroscopy and IR spectrometry. It was shown that the IR spectra of the compounds contain bands of the corresponding stretching vibrations of the alcoholic hydroxyl group, enol hydroxyl, amide and ketone groups. In the 1H NMR spectra of the compounds, along with the signals of aromatic protons in the C5 substituent and related groups, characteristic peaks are observed, indicating the formation of the corresponding derivatives of 3-hydroxy-3-pyrrolin-2-ones. It was noted that in the case of the synthesis of 5-aryl-3-hydroxy-1-(2-hydroxypropyl)-4-(furyl-2-carbonyl)-3-pyrrolin-2-ones, the signal of the methine proton at the C5 position of the heterocycle is cleaved in 1H NMR spectra compounds as a result of the appearance of a second chiral center in the 2-hydroxypropyl radical. Elemental analysis was performed for the synthesized compounds.


ChemInform ◽  
2010 ◽  
Vol 25 (24) ◽  
pp. no-no
Author(s):  
V. S. PARMAR ◽  
A. VARDHAN ◽  
S. K. SHARMA ◽  
N. K. SHARMA ◽  
K. S. BISHT

1978 ◽  
Vol 43 (1) ◽  
pp. 250-256
Author(s):  
Jaroslava Podehradská ◽  
Milan Hájek ◽  
Slavoj Hála
Keyword(s):  
1H Nmr ◽  

1999 ◽  
Vol 23 (1) ◽  
pp. 48-49
Author(s):  
Martín A. Iglesias Arteaga ◽  
Carlos S. Pérez Martinez ◽  
Roxana Pérez Gil ◽  
Francisco Coll Manchado

The assignment of 13C and 1H NMR signals of synthetic (25 R)-5α-spirostanes is presented; the main effects on chemical shifts due to substitution at C-23 are briefly discussed.


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