Investigations in the thiophtene series report 12. Synthesis of thieno[3,4]thiophene-2-carboxylic acid and NMR spectra of the isomeric thienothiophenes

1968 ◽  
Vol 17 (8) ◽  
pp. 1729-1735
Author(s):  
V. P. Litvinov ◽  
G. Fraenkel
Keyword(s):  
Carboxylic Acid ◽  
Nmr Spectra ◽  
Series Report

Synthesis of Linear Steroid Oligoesters Based on Etienic Acid

2002 ◽  
Vol 67 (11) ◽  
pp. 1709-1718 ◽  
Author(s):  
Miroslav Reschel ◽  
Miloš Buděšínský ◽  
Ivan Černý ◽  
Vladimír Pouzar ◽  
Pavel Drašar
Keyword(s):  
Carboxylic Acid ◽  
Nmr Spectra ◽  
Mixed Anhydride

Linear oligoesters based on etienic acid (3β-hydroxyandrost-5-ene-17β-carboxylic acid) containing 2-4 steroid units were prepared employing mixed anhydride esterification. NMR spectra of the oligomeric steroids have been fully assigned.

Anhydrous Chromium(III) Carboxylates: Reactions of CrO3 with Carboxylic Acid Anhydrides

1983 ◽  
Vol 38 (1) ◽  
pp. 42-44 ◽  
Author(s):  
Ramesh Kapoor ◽  
Ramneek Sharma
Keyword(s):  
Magnetic Susceptibility ◽  
Carboxylic Acid ◽  
Nmr Spectra ◽  
Octahedral Geometry ◽  
H Nmr ◽  
Chromium Vi ◽  
Carboxylate Groups ◽  
Different Types ◽  
Pure Chromium ◽  
Acid Anhydrides

Abstract Chromium(VI) oxide reacts with excess of carboxylic acid anhydrides [(RCO)2O where R = CH3, C2H5, n-C3H7 and CHCl2] to give pure chromium(III) carboxylates. Their IR and 1H NMR spectra suggest the presence of two different types of carboxylate groups. Magnetic susceptibility and absorption spectra favour an octahedral geometry around Cr.

Experimental and calculated 1H, 13C and 31P NMR spectra of pyridine-2-phosphono-4-carboxylic acid

2003 ◽  
Vol 648 (3) ◽  
pp. 215-224 ◽  
Author(s):  
Katarzyna Chruszcz ◽  
Małgorzata Barańska ◽  
Krzysztof Czarniecki ◽  
Bogdan Boduszek ◽  
Leonard M Proniewicz
Keyword(s):  
Carboxylic Acid ◽  
Nmr Spectra ◽  
31P Nmr ◽  
31P Nmr Spectra ◽  
13C And 31P Nmr

Dioxobis(Carboxylato)Chromium(VI) and Oxo(Carboxylato)Chromium(III): Reactions of CrO3 with Carboxylic Acid Anhydrides

1984 ◽  
Vol 39 (12) ◽  
pp. 1702-1705 ◽  
Author(s):  
Ramesh Kapoor ◽  
Ramneek Sharma ◽  
Pratibha Kapoor
Keyword(s):  
Carboxylic Acid ◽  
Ir Spectra ◽  
Low Temperatures ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Equimolar Ratio ◽  
H Nmr ◽  
Chromium Vi ◽  
Polar Organic Solvents ◽  
Acid Anhydrides

Reactions of carboxylic acid anhydrides [(RCO)2O where R = CH3, C2H5, n-C3H7 and CHCl2] with excess of chromium (VI) oxide at low temperatures yield chromyl carboxylates, CrO2(OOCR)2. These compounds are non-conducting in polar organic solvents. IR spectra suggest the presence of both unidentate and bidentate carboxylato groups and discrete Cr = 0 units. The 1H NMR spectra show the presence of only one type of carboxylato group.Reactions of carboxylic acid anhydrides with CrO3 in equimolar ratio yield reduced chromium(III) com pounds o f the type CrO(OOCR) at room temperature. Their millimolar solutions in C6H5NO2, CH3NO2 and CH3CN are non-conducting. IR spectra, magnetic susceptibility and some other properties have been investigated. Both types of compounds are polymeric in nature having covalent structures.

scholarly journals Isolation and Structural Elucidation of Nitrogenous Secondary Metabolites from Terrestrial and Marine Streptomyces spp

2017 ◽  
Vol 12 (3) ◽  
pp. 1934578X1701200
Author(s):  
Mohamed Shaaban ◽  
Khaled A. Shaaban ◽  
Elisabeth Helmke ◽  
Iris Grün-Wollny ◽  
Hartmut Laatsch
Keyword(s):  
Carboxylic Acid ◽  
Nmr Spectra ◽  
Acid Methyl Ester ◽  
2D Nmr ◽  
Benzene Derivatives ◽  
Streptomyces Spp ◽  
Acid Methyl ◽  
2D Nmr Spectra ◽  
New Compounds ◽  
Related Compounds

Screening and chromatography of extracts from a terrestrial and a marine-derived streptomycete yielded two new nitrogenous benzene derivatives, namely ( S)- N-[3-hydroxy-1-(4-hydroxyphenyl)-propyl]-acetamide (1a), and ( R)-2-(1-methyl-2-oxopropylamino)-benzoic acid (2). Additionally, eight known compounds were isolated, 2-acetamidophenol, phenazine-1-carboxylic acid, phenazine-1-carboxylic acid methyl ester, perlolyrin, tyrosol, uracil, and anthranilic acid. The structures of the new compounds were deduced from high resolution mass, 1D and 2D NMR spectra and by comparison with related compounds from the literature. The absolute configuration of 1a and 2 was determined by comparison of experimental and calculated CD and ORD data.

scholarly journals Synthesis and biological studies for some heterocyclic compounds derived from 2-Morpholino-1,8- naphthyridine-4-carboxylic acid

2013 ◽  
Vol 10 (3) ◽  
pp. 758-765 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Carboxylic Acid ◽  
1H Nmr ◽  
Heterocyclic Compounds ◽  
Nmr Spectra ◽  
1H Nmr Spectra ◽  
Starting Material ◽  
Good Activity ◽  
Biological Studies

New heterocyclic compounds derived from 2-Morpholino-1,8-naphthyridine-4-carboxylic acid such as oxadiazolo, thiadiazolo – thione and triazolo-thione have been prepared and characterized on the basis of IR and 1H NMR spectra data. The hydrizide compound was utilized as a starting material for preparing of these compounds. The second part of this study involves the biological studies of some of these naphthyridine derivatives by using three different kinds of bacteria namely: Staphylococcus aureus, Pseudomonas aeruglnosa and Escherichia coli. The data indicated that some of these compounds have a good activity against the tested bacteria in comparison to antibiotics.

scholarly journals Convenient approaches to the synthesis of 6-amino- and 6-oxoimidazo[4,5-b]pyrazolo[3,4-e]pyridines

2021 ◽  
Vol 19 (1(73)) ◽  
pp. 10-15
Author(s):  
G. G. Yakovenko ◽  
M. V. Vovk
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acid ◽  
Ir Spectra ◽  
Carboxylic Acids ◽  
1H Nmr ◽  
Nmr Spectra ◽  
1H Nmr Spectra ◽  
Biologically Active ◽  
Spectral Measurements ◽  
Absorption Bands

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

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