scholarly journals Grindstone Chemistry: An Efficient and Green Synthesis of 2-Amino-4H-benzo[b]pyrans

2017 ◽  
Vol 2 (2) ◽  
pp. 78 ◽  
Author(s):  
Arumugam Thangamani

A single step, mild, environmentally friendly green method has been developed for the synthesis of physiologically active 2-amino-4H-benzo[b]pyrans employing solid sodium ethoxide as catalyst under solvent free conditions at room temperature via grinding. The procedure is efficient, time saving and gives high yields. The structures and purity of these compounds were confirmed by elemental analysis and spectral analysis (FT-IR, 1H-NMR and 13C-NMR).

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Amulrao Borse ◽  
Mahesh Patil ◽  
Nilesh Patil ◽  
Rohan Shinde

An expeditious, one-pot method for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones using a mixture of phosphorus pentoxide-methanesulfonic acid (Eaton’s reagent) at room temperature under solvent-free conditions is described. The salient features of this method include short reaction time, green aspects, high yields, and simple procedure.


2009 ◽  
Vol 87 (9) ◽  
pp. 1209-1212 ◽  
Author(s):  
Hongshe Wang ◽  
June Zeng

Chalcones are useful intermediates in organic synthesis and exhibit a large number of different biological activities. Chalcones have been synthesized in high yields by Claisen–Schmidt condensation of substituted acetophenones with various aromatic aldehydes in the presence of 10 mol% of iodine at room temperature by grinding under solvent-free conditions.


2010 ◽  
Vol 88 (2) ◽  
pp. 150-154 ◽  
Author(s):  
Sudarshan Das ◽  
Matiur Rahman ◽  
Dhiman Kundu ◽  
Adinath Majee ◽  
Alakananda Hajra

A sulfonic-acid-functionalized ionic liquid is used as a Brønsted acid catalyst for the efficient synthesis of indole derivatives in good-to-high yields at room temperature under solvent-free conditions. The catalyst can be reused for ten consecutive runs without significant loss of activity.


2021 ◽  
Vol 37 (5) ◽  
pp. 1178-1186
Author(s):  
Rakesh Kumar ◽  
Gursharan Singh

MoCl5 reactions with 4-methylpyridine/2-methylpyridine/1-methylimidazole in THF in 1:1/1:2 stoichiometric ratios, at room temperature were carried out. The following products were synthesized: MoO2Cl(C6H7N), 1;Mo2O2Cl5(C6H7N)2(C4H8O)2,2; Mo4O4Cl4(C6H7N)3(C4H8O)2, 3 and Mo2O4Cl4(C4H6N)2(C4H8O), 4. These compounds have been investigated by FT-IR (transmission mode), FT-1H NMR, FT -13C NMR, microbiological, LC-MS and elemental (C, H, N, Mo, Cl) studies. In view of the sensitivity of all the reactants and products towards oxidation/hydrolysis by air/moisture, all the reactions and products were handled using dry nitrogen atmosphere in vacuum line. LC-MS and elemental studies agree with the formulae of compounds.


Author(s):  
Nileshkumar D. Vala ◽  
Hardik H. Jardosh ◽  
Manish P. Patel

A series of 8 derivatives of chromene 5a-h synthesized via one-pot cyclocondensation reaction of N-allyl quinolones, α/β naphthol and malononitrile. And 8 derivatives of pyrimidines 8a-h bearing N-allyl quinolone have been synthesized by N-allyl quinolones, ethylacetoacetate, thiourea/urea in the presence of zinc triflate as less toxic catalyst. This methodology allowed the high conversion of product at room temperature. Titled derivatives were elucidated by FT-IR, 1H NMR, 13C NMR, elemental analysis, and mass spectral data.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4908
Author(s):  
Rubina Munir ◽  
Noman Javid ◽  
Muhammad Zia-ur-Rehman ◽  
Muhammad Zaheer ◽  
Rahila Huma ◽  
...  

In this article, a synthesis of N’-(benzylidene)-2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazides and their structural interpretation by NMR experiments is described in an attempt to explain the duplication of some peaks in their 1H- and 13C-NMR spectra. Twenty new 6-methyl-1H-pyrazolo[3,4-b]quinoline substituted N-acylhydrazones 6(a–t) were synthesized from 2-chloro-6-methylquinoline-3-carbaldehyde (1) in four steps. 2-Chloro-6-methylquinoline-3-carbaldehyde (1) afforded 6-methyl-1H-pyrazolo[3,4-b]quinoline (2), which upon N-alkylation yielded 2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetate (3). The hydrazinolysis of 3 followed by the condensation of resulting 2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazide (4) with aromatic aldehydes gave N-acylhydrazones 6(a–t). Structures of the synthesized compounds were established by readily available techniques such as FT-IR, NMR and mass spectral studies. The stereochemical behavior of 6(a–t) was studied in dimethyl sulfoxide-d6 solvent by means of 1H NMR and 13C NMR techniques at room temperature. NMR spectra revealed the presence of N’-(benzylidene)-2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazides as a mixture of two conformers, i.e., E(C=N)(N-N) synperiplanar and E(C=N)(N-N)antiperiplanar at room temperature in DMSO-d6. The ratio of both conformers was also calculated and E(C=N) (N-N) syn-periplanar conformer was established to be in higher percentage in equilibrium with the E(C=N) (N-N)anti-periplanar form.


2020 ◽  
Author(s):  
Arefeh Dehghani Tafti ◽  
Bi BiFatemeh Mirjalili ◽  
Abdolhamid Bamoniri ◽  
Naeimeh Salehi

Abstract Nano-egg shell/Ti(IV) (NEST) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole [DHPP] derivatives. The characterization of NEST was performed using Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Energy-Dispersive X-ray Spectroscopy (EDX), and Thermo Gravimetric Analysis (TGA). DHPPs were synthesized in the presence of NEST via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are easy work-up, high yields of pure products without the use of any toxic organic solvents, mild condition and short reaction times.


2021 ◽  
Vol 40 (3) ◽  
pp. 28-42
Author(s):  
Y. Walid AlBizreh ◽  
rasha Almostafa ◽  
Malak ALJoubbeh

The boiled tea leaves residual was modified with oleum of weight 1:1 to prepare an adsorbent that is capable to adsorb nicotine on its surface. The surface properties of the sample were studied by using the FT-IR spectroscopy after each treatment resulting obvious peaks that indicate the modification of the sample with oleum and the adsorption of nicotine on its surface. The concentration of nicotine in the prepared solutions was measured by the use of spectral analysis. The change of nicotine΄s adsorption was studied with the change of time. An increase in the adsorbed amount was noticed until the equilibrium was reached after 24hours. In addition, an increase of the adsorbed amount of nicotine with the increase of its initial concentration was observed at the room temperature. The experimental data corresponded with adsorption models of Langmuir, Freundlish and Temkin, besides, a mechanism of the adsorption of nicotine was suggested to occur with the participation of the two nitrogen atoms.


2021 ◽  
Vol 11 (2-S) ◽  
pp. 89-97
Author(s):  
Vishal Mane ◽  
Dhanjay Mane

The [DBN][HSO4] -promoted Knoevenagel condensation followed by cyclization protocol has been developed for the first time by a successive reaction of aldehydes, dimedone and malononitrile to afford 2-Amino-4H-pyrans derivatives in high to excellent yields at room temperature. The synergic couple of microwave and ionic liquid provided the capability to allow a variability of functional groups, short reaction times, easy workup, high yields, recyclability of the catalyst, and solvent-free conditions, thus providing economic and environmental advantages. Keywords: [DBN][HSO4], Environmentally benign, 2-Amino-4H-pyrans, Knoevenagel condensation, Microwave irradiation


RSC Advances ◽  
2016 ◽  
Vol 6 (100) ◽  
pp. 98365-98368 ◽  
Author(s):  
Hai Truong Nguyen ◽  
Phuong Hoang Tran

An efficient and green method was developed for the acylation of secondary alcohols, phenols and naphthols using deep eutectic solvent [CholineCl][ZnCl2]3 as a catalyst at room temperature under solvent-free conditions.


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