scholarly journals Synthetic Derivatives of Natural Alkaloid Harmine

2016 ◽  
Vol 11 (3) ◽  
pp. 199
Author(s):  
N.M. Ismagulova ◽  
Zh.S. Nurmaganbetov ◽  
A.Zh. Turmukhambetov ◽  
T.S. Seitembetov ◽  
S.M. Adekenov
Keyword(s):  
Indole Alkaloid ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Peganum Harmala ◽  
Underground Part ◽  
X Ray ◽  
Natural Alkaloid ◽  
First Time ◽  
Synthetic Derivatives ◽  
Derivatives Of

The indole alkaloid harmine was extracted from underground part of <em>Peganum harmala L.</em> With the purpose of obtaining the new biological active derivatives on base of alkaloid harmine the chemical modification was carried out. The p-toluolsulfochlorid, p-toluolsulfoacid, hydrochloric, sulfuric, nitric acids, dioxide selenium and phthalic anhydride have been chosen as modifiers. For the first time quaternary ammonium salts, derivatives of N-oxide and N (2)-oxyharminiumphthalate harmine are synthesized. The structure of the synthesized compounds is determined by methods of the spectral analysis and X-ray analysis. Antimicrobic and phagocytosis stimulating activities of isolated alkaloids and their derivatives are investigated.

scholarly journals Base-free enantioselective SN2 alkylation of 2-oxindoles via bifunctional phase-transfer catalysis

2021 ◽  
Vol 17 ◽  
pp. 2287-2294
Author(s):  
Mili Litvajova ◽  
Emiliano Sorrentino ◽  
Brendan Twamley ◽  
Stephen J Connon
Keyword(s):  
Hydrogen Bond ◽  
Ad Hoc ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Quaternary Ammonium Salts ◽  
Enantioselective Synthesis ◽  
Ammonium Salts ◽  
Synthetic Utility ◽  
First Time ◽  
Derivatives Of

N-Protected oxindole derivatives of unprecedented malleability bearing ester moieties at C-3 have been shown to participate in enantioselective phase-transfer-catalysed alkylations promoted by ad-hoc designed quaternary ammonium salts derived from quinine bearing hydrogen-bond donating substituents. For the first time in such phase-transfer-catalysed enolate alkylations, the reactions were carried out under base-free conditions. It was found that urea-based catalysts outperformed squaramide derivatives, and that the installation of a chlorine atom adjacent to the catalyst’s quinoline moiety aided in avoiding selectivity-reducing complications related to the production of HBr in these processes. The influence of steric and electronic factors from both the perspective of the nucleophile and electrophile were investigated and levels of enantiocontrol up to 90% ee obtained. The synthetic utility of the methodology was demonstrated via the concise enantioselective synthesis of a potent CRTH2 receptor antagonist.

Synthesis of Galactomannan Sulfate-Citrate

2022 ◽  
Vol 1049 ◽  
pp. 218-223
Author(s):  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Anna S. Kazachenko
Keyword(s):  
Biological Activity ◽  
Ftir Spectroscopy ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Mixed Ester ◽  
First Time ◽  
Derivatives Of

Sulfated derivatives of polysaccharides have anticoagulant, hypolipedimic and other biological activity. In this work, a complex mixed ester of galactomannan, its sulfate-citrate, was obtained for the first time. The introduction of citrate and sulfate groups was proved by FTIR spectroscopy by the appearance of corresponding absorption bands. It was shown by X-ray diffraction that the introduction of the citrate group leads to the amorphization of the galactomannan structure.

An Effective Synthesis of N,N-Diphenyl Carbazolium Salts

Synlett ◽  
2017 ◽  
Vol 29 (10) ◽  
pp. 1314-1318 ◽  
Author(s):  
Charles Diesendruck ◽  
Sinai Aharonovich ◽  
Nansi Gjineci ◽  
Dario Dekel
Keyword(s):  
Positive Charge ◽  
Quaternary Ammonium Salts ◽  
Simple Approach ◽  
Ammonium Salts ◽  
State Structure ◽  
Pi Systems ◽  
Effective Synthesis ◽  
Short Time ◽  
First Time ◽  
General Method

Tetraaryl ammonium salts are a synthetic challenge, since there is no general method for the arylation of triaryl amines. Contrary to other quaternary ammonium salts, tetraaryl ammonium salts should be very chemically stable. The ipso carbons are not very electrophilic, since the positive charge is distributed throughout the pi systems and they have no acidic β hydrogens. Here we demonstrate a simple approach to N,N-diphenyl carbazolium salts using only three synthetic steps, allowing for an easy production of these salts in large amounts and in a relatively short time. In addition, we study the Cu(I) catalyzed multi-arylation of 2,2’-diaminobiphenyl, focusing on the regioselectivity of each step. Finally, we characterize, for the first time, the solid state structure of a tetraaryl ammonium salt.

Physical Properties of Nylon 66/Organoclay Nanocomposites

2006 ◽  
Vol 530-531 ◽  
pp. 702-708 ◽  
Author(s):  
Edcleide Maria Araújo ◽  
K.D. Araujo ◽  
Taciana Regina de Gouveia Silva
Keyword(s):  
Mechanical Properties ◽  
Infrared Spectroscopy ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
X Ray Diffraction ◽  
Rheological Characterization ◽  
Nylon 66 ◽  
X Ray ◽  
Organically Modified

Nanocomposites containing nylon 66 and montmorillonite clay organically modified with quaternary ammonium salts were obtained via direct melt intercalation. A montmorillonite sample from Boa Vista/PB, Northeast of Brazil, was treated with three types of quaternary ammonium salts such as Genamin, Praepagen and Cetremide. After the treatment, the powder was characterized by X-ray diffraction (XRD). The produced nanocomposites were characterized by Torque Rheometer, Infrared Spectroscopy (FTIR), mechanical properties and HDT. The obtained results for rheological characterization showed that the nanocomposites did not present deterioration with the presence of modified clay. Generally, the mechanical properties of tensile of the systems presented superior values compared to that of pure Ny 66. HDT's properties presented very interesting values for the nanocomposites and significantly larger than for pure nylon 66.

Influence of Organoclay on the Physical Properties of Polyethylene Nanocomposites

2006 ◽  
Vol 530-531 ◽  
pp. 709-714 ◽  
Author(s):  
Edcleide Maria Araújo ◽  
Amanda D. de Oliveira ◽  
Renata Barbosa ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Mechanical Properties ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Polyethylene Matrix ◽  
X Ray ◽  
Ft Ir

In this work, polyethylene/montmorillonite clay nanocomposites were produced by melt intercalation. The clays were treated with quaternary ammonium salts and then treated and untreated clays were introduced in polyethylene. The clays were characterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The nanocomposites were characterized by mechanical and flammability properties. The results showed that the mechanical properties were improved by introduction of organoclay in polyethylene matrix. By adding only 3wt% montmorillonite, the burning rate of the nanocomposites was reduced by 17% in relation to PE matrix.

Iodo-bis(quaternary ammonium) salts. Potential cartilage-selective x-ray contrast agents

1976 ◽  
Vol 19 (11) ◽  
pp. 1349-1352 ◽  
Author(s):  
Steven P. Van Ootegham ◽  
Ronald G. Smith ◽  
G. Doyle Daves ◽  
Edwin M. Chang ◽  
Aziza El-Mazati ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
X Ray
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