scholarly journals Comparative Study on Conventional and Ultrasound Irradiation Promoted Synthesis of 2,3-Disubstitutedquinoxaline Derivatives

2018 ◽  
Vol 28 (3) ◽  
pp. 141
Author(s):  
Ahmed Mutanabbi Abdula ◽  
Ghazwan Ali Salman ◽  
Hamid H. Mohammed
Keyword(s):  
13C Nmr ◽  
Ultrasonic Irradiation ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Conventional Heating ◽  
Heating Method ◽  
Quinoxaline Derivatives ◽  
Ft Ir ◽  
Ultrasound Assisted ◽  
Good Percentage

A series of ten chalcone-substituted quinoxalines (4a-e), (3a-e) starting from 1-(phenylquinoxalin-2-yl)ethanone and 1-(3-methylquinoxalin-2-yl)ethanone have been synthesized using conventional heating and ultrasound-assisted methods. Furthermore, novel of five quinoxaline derivatives including pyrazoline, isoxazole, pyrimidin-2-one, N-acylpyrazoline and pyridin-2-one moieties were also prepared from the reaction of chalcone compound 4a with different cyclization reagents using the same strategy. The structures of all synthesized compounds were established on the basis of FT-IR, 1H-NMR and 13C-NMR. The ultrasonic irradiation method provide several advantages over conventional heating method, including shorter reaction times (30-90 min.) and good percentage yields (65% - 88%), comparing with conventional protocol (5 to 20 hrs. with 30% to 55% reaction yields).

scholarly journals Synthesis of 5-Nitro-1,2,4-Triazol-3-One Via: Conventional Heating, Microwave and Ultrasonication

2021 ◽  
Vol 5 (1) ◽  
Keyword(s):  
Nitric Acid ◽  
Formic Acid ◽  
Laboratory Experiment ◽  
Conventional Heating ◽  
Heating Method ◽  
Microwave Assisted ◽  
Semicarbazide Hydrochloride ◽  
Ultrasound Assisted

In this laboratory experiment 2,4-dihydro-3H-1,2,5-Triazol-3-one(TO) was synthesized using mixture of semicarbazide hydrochloride(SC.HCl) and formic acid in 1:3 mole ratio. TO was further nitrated using 70% nitric acid (HNO3) to produce2,4-dihydro-3H-5-nitro-1,2,5-triazol-3-one(NTO). For the nitration reaction three techniques were employed: conventional heating, microwave assisted and ultrasound assisted reaction. It was found that the extent of gases generation during the reaction was reduced when microwave and ultrasound was employed as compared to the conventional heating method. The time taken for the completion of the reaction was only 15 min when microwave was used.

Synthesis of Guerbet Alcohol Acrylate Aided by Microwave

2013 ◽  
Vol 860-863 ◽  
pp. 1007-1011
Author(s):  
Xu Dong ◽  
Xiao Hui Zhang ◽  
Ming Hui Zhou ◽  
Wen Huan Wang ◽  
Jing Chang Wang
Keyword(s):  
Acrylic Acid ◽  
Microwave Irradiation ◽  
1H Nmr ◽  
13C Nmr ◽  
Conventional Heating ◽  
Reaction Parameters ◽  
Reaction Conditions ◽  
Polymerization Inhibitor ◽  
Ft Ir ◽  
Esterification Rate

Guerbet alcohol acrylate was synthesized using acrylic acid and guerbet alcohol alcohols as reactants, p-toluenesulfonic acid as catalyst, hydroquinone as polymerization inhibitor and toluol as solvent by microwave irradiation heating instead of the conventional heating with oil bath. The structure of product was characterized by FT-IR, 1H-NMR, 13C-NMR and the effect of different reaction parameters was discussed in this paper. A procedure for the generation of fairly clean guerbet alcohol acrylate is well developed and the results indicated that under the appropriate reaction conditions the esterification rate of guerbet alcohol acrylate could be achieved above 98%.

scholarly journals Lignin and Cellulose Extraction from Vietnam’s Rice Straw Using Ultrasound-Assisted Alkaline Treatment Method

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Ngo Dinh Vu ◽  
Hang Thi Tran ◽  
Nhi Dinh Bui ◽  
Cuong Duc Vu ◽  
Hung Viet Nguyen
Keyword(s):  
Rice Straw ◽  
Ultrasonic Irradiation ◽  
Extraction Method ◽  
Treatment Method ◽  
Alkaline Treatment ◽  
Lignin Extraction ◽  
Ultrasonic Assisted ◽  
Ft Ir ◽  
Ultrasound Assisted ◽  
Modern Analytical

The process of cellulose and lignin extraction from Vietnam’s rice straw without paraffin pretreatment was proposed to improve economic efficiency and reduce environmental pollution. Treatment of the rice straw with ultrasonic irradiation for 30 min increased yields of lignin separation from 72.8% to 84.7%. In addition, the extraction time was reduced from 2.5 h to 1.5 h when combined with ultrasonic irradiation for the same extraction yields. Results from modern analytical methods of FT-IR, SEM, EDX, TG-DTA, and GC-MS indicated that lignin obtained by ultrasound-assisted alkaline treatment method had a high purity and showed a higher molecular weight than that of lignin extracted from rice straw without ultrasonic irradiation. The lignin and cellulose which were extracted from rice straw showed higher thermal stability with 5% degradation at a temperature of over 230°C. The ultrasonic-assisted alkaline extraction method was recommended for lignin and cellulose extraction from Vietnam’s rice straw.

scholarly journals Ultrasound-Assisted, Base-Catalyzed, Homogeneous Reaction for Ferulic Acid Production from γ-Oryzanol

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Hoa Thi Truong ◽  
Manh Van Do ◽  
Long Duc Huynh ◽  
Linh Thi Nguyen ◽  
Anh Tuan Do ◽  
...  
Keyword(s):  
Ferulic Acid ◽  
Ultrasonic Irradiation ◽  
Heterogeneous Systems ◽  
Low Frequency ◽  
Ultrasound Irradiation ◽  
Homogeneous Reaction ◽  
Acid Yield ◽  
Ultrasound Assisted ◽  
Ferulic Acid Production ◽  
Hydrolysis Of

A method for producing ferulic acid by ultrasound-assisted, homogeneous, base-catalyzed hydrolysis of γ-oryzanol was developed. Experiments were conducted using various reaction temperatures and ratios of γ-oryzanol to base catalyst in both homogeneous and heterogeneous systems. The reaction performed without ultrasound under the homogeneous conditions of potassium hydroxide/γ-oryzanol ratio (wt/wt) 20 : 1 and 75°C gave a ferulic acid yield of 83.3% in 3 h. Acceleration of the homogeneous reaction using ultrasound irradiation at 20 (horn type) and 200 kHz (planar type) was explored by evaluating the kinetic parameters. At 30°C, the ratios of ultrasonic irradiation at low (20 kHz, 50 W) and high (200 kHz, 50 W) frequencies versus those of the heating method increased by 2.0- and 1.4-fold in comparison with those at 60°C, respectively. The contribution of ultrasonic irradiation (50 W) to the hydrolysis reaction decreased with increase of temperature. However, irradiation at 20 kHz and a power of 180 W gave a 94% ferulic acid yield at 60°C in 3 h. These results indicate that the use of low frequency (horn type and high-power irradiation) enabled yields higher than 90% to be obtained.

scholarly journals Comparative Studies on Conventional and Ultrasound-Assisted Synthesis of Novel Homoallylic Alcohol Derivatives Linked to Sulfonyl Dibenzene Moiety in Aqueous Media

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Mohamed F. Mady ◽  
Ahmed A. El-Kateb ◽  
Ibrahim F. Zeid ◽  
Kåre B. Jørgensen
Keyword(s):  
Spectral Data ◽  
Comparative Studies ◽  
Carbonyl Compounds ◽  
Aqueous Media ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Reaction Conditions ◽  
Homoallylic Alcohols ◽  
Ultrasound Assisted ◽  
High Yields

Novel homoallylic alcohols incorporating sulfone moieties were synthesized by the treatment of different carbonyl compounds with allylic bromides in aqueous mediaviasonochemical Barbier-type reaction conditions. Sulfonation ofα-bromoketones with sodium benzenesulfinate in presence of CuI/2,6-lutidine rapidly gaveβ-keto-sulfones in good yields. In general, ultrasound irradiation offered the advantages of high yields, short reaction times, and simplicity compared to the conventional methods. The structures of all the compounds were confirmed by analytical and spectral data.

A greener procedure for the synthesis of α-ureidophosphonates under ultrasound irradiation. An X-ray crystallographic study

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 99775-99780 ◽  
Author(s):  
Abdeslem Bouzina ◽  
Malika Berredjem ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Nour-eddine Aouf
Keyword(s):  
Ultrasonic Irradiation ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
One Pot ◽  
X Ray ◽  
Catalyst Free ◽  
Crystallographic Study ◽  
Three Component Reaction

The synthesis of α-ureidophosphonates via a one-pot three-component reaction using ultrasonic irradiation under solvent- and catalyst-free conditions at 75° is developed. The products were obtained in excellent yields within short reaction times.

Water-Mediated Green Synthesis of Benzimidazoles Using Pyruvic Acid: A Comparable Study of Ultra-sonication versus Conventional Heating

2021 ◽  
Vol 18 ◽  
Author(s):  
Santosh Rangnath Deshmukh ◽  
Archana Subhash Nalkar ◽  
Shankar Ramchandra Thopate
Keyword(s):  
Pyruvic Acid ◽  
Reaction Times ◽  
Acid Catalyst ◽  
Aromatic Aldehydes ◽  
Ultrasound Irradiation ◽  
Conventional Heating ◽  
Benzimidazole Derivatives ◽  
Green Protocol ◽  
Catalyst Metal ◽  
Wide Range

: An efficient and green protocol has been introduced for the synthesis of benzimidazole derivatives using a pyruvic acid catalyst in the presence of water. Pyruvic acid catalyses the reaction of aromatic aldehydes with o-phenylenediamine efficiently, and products were obtained in good to excellent yields under sonication (50 oC) or under conventional heating (50 oC). The advantages of this synthetic methodology are the use of eco-friendly, commercially cheap, biodegradable catalyst, metal-free and Lewis acid-free mild reaction conditions with excellent yields, short reaction times, and compatible with a wide range of electronically diverse substrates. Pyruvic acid in water as a catalyst under ultrasound irradiation can be a better alternative to synthesize benzimidazole derivatives than some of the traditional methods.

Highly effective synthesis of dibromide of (+)-(1R, 2R)-and (-)-(1S, 2S) -1,2- diphenyl-1,2-ethylenediammonium (DPEN∙2HBr) assisted by microwave

2020 ◽  
Vol 07 ◽  
Author(s):  
Jeyson Andrés Cortés Mitte ◽  
Andrés Felipe Ojeda Delgado ◽  
Luis Alberto Lenis Velásquez
Keyword(s):  
Melting Point ◽  
Microwave Heating ◽  
13C Nmr ◽  
Optical Resolution ◽  
Conventional Heating ◽  
1H And 13C Nmr ◽  
Highly Effective ◽  
Effective Synthesis ◽  
Ft Ir ◽  
Optical Rotations

Abstract:: In this work, the chiral salts (R,R)- and (S,S)-dibromide of 1,2-diphenyl-1,2-ethylenediammonium (R,R)-9 and (S,S)-9 were synthesized, both by conventional and microwave heating, obtaining yields and optical rotations (c 0.43, H2O) of 92%, +17.48° and 90%, -17.50°, respectively (conventional heating by 24 h) and 92%, +17.52° and 89%, -17.44°, respectively (microwave heating by 1.4 h). These compounds were synthesized by means of the racemic intermediate (±)- iso-amarine (±)-6, leading to the separation of their enantiomers, by fractional optical resolution and using as resolution agents the enantiomers of (+)-(S)- and (-)-(R)-MA 3. The starting reagents were benzaldehyde and 28-30% NH4OH, which are economical and commercially affordable. All synthesized compounds were characterized by melting point, solubility, UV-vis, FT-IR (ATR). Imidazoline (±)-6 and salts (R,R)-9 and (S,S)-9 were additionally characterized by 1H and 13C NMR. Polarimetry was determined to (R,R)-(+)-6, (S,S)-(-)-6, (S,R,R)-(+)-7, (R,S,S)-(-)-7, (S,S)-(+)-8, (R,R)-(-)-8, (R,R)-(+)-9 and (S,S)-(-)-9 compounds.

Synthesis of Natural Surfactant of Sodium Lignosulfonate from Rice Husk Lignin by Ultrasound Assisted - Sulfonation

2018 ◽  
Vol 775 ◽  
pp. 20-25 ◽  
Author(s):  
Anwar Ma'ruf ◽  
Bambang Pramudono ◽  
Nita Aryanti
Keyword(s):  
Rice Husk ◽  
Ultrasonic Irradiation ◽  
Ftir Spectra ◽  
Conventional Heating ◽  
Sodium Lignosulfonate ◽  
Natural Surfactant ◽  
Ultrasound Assisted ◽  
Lower Temperature

Sodium lignosulfonate (SLS) is one of natural surfactant that can be modified from lignin. The utilization of natural surfactant of SLS is widely studied by researchers. This paper will study the synthesis of a natural surfactant of SLS from rice husk lignin by ultrasound assisted – sulfonation and the characteristics of SLS based on FTIR spectra. The reaction was carried out at the temperature of 60 °C and the time of 30 minutes. From the experiment can be concluded that sulfonation process with ultrasonic irradiation has advantages compared with conventional heating, i.e. lower temperature, shorter time and higher yield.

Synthesis of some Novel Imidazoles Catalyzed by Co3O4 Nanoparticles and Evaluation of their Antibacterial Activities

2018 ◽  
Vol 21 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Mohammad A. Ghasemzadeh ◽  
Mohammad H. Abdollahi-Basir ◽  
Zahra Elyasi
Keyword(s):  
Cobalt Oxide ◽  
Ammonium Acetate ◽  
Reaction Times ◽  
Antibacterial Activities ◽  
Primary Amines ◽  
Oxide Nanoparticles ◽  
Co3o4 Nanoparticles ◽  
Cobalt Oxide Nanoparticles ◽  
Ft Ir ◽  
Tetrasubstituted Imidazoles

Aim and Objective: The multi-component condensation of benzil, primary amines, ammonium acetate and various aldehydes was efficiently catalyzed using cobalt oxide nanoparticles under ultrasonic irradiation. This approach describes an effective and facile method for the synthesis of some novel 1,2,4,5-tetrasubstituted imidazole derivatives with several advantages such as high yields and short reaction times and reusability of the catalyst. Moreover, the prepared heterocyclic compounds showed high antibacterial activity against some pathogenic strains. Materials and Method: The facile and efficient approaches for the preparation of Co3O4 nanoparticles were carried out by one step method. The synthesized heterogeneous nanocatalyst was characterized by spectroscopic analysis including EDX, FE-SEM, VSM, XRD and FT-IR analysis. The as-synthesized cobalt oxide nanoparticles showed paramagnetic behaviour in magnetic field. In addition, the catalytic influence of the nanocatalyst was examined in the one-pot reaction of primary amines, benzil, ammonium acetate and diverse aromatic aldehydes under ultrasonic irradiation. All of the 1,2,4,5-tetrasubstituted imidazoles were investigated and checked with m.p., 1H NMR, 13C NMR and FT-IR spectroscopy techniques. The antibacterial properties of the heterocycles were evaluated in vitro by the disk diffusion against pathogenic strains such as Escherichia coli (EC), Bacillus subtillis (BS), Staphylococcus aureus (SA), Salmonellatyphi (ST) and Shigella dysentrae (SD) species. Results: In this research cobalt oxide nanostructure was used as a robust and green catalyst in the some novel imidazoles. The average particle size measured from the FE-SEM image is found to be 20-30 nm which confirmed to the obtained results from XRD pattern. Various electron-donating and electron-withdrawing aryl aldehydes were efficiently reacted in the presence of Co3O4 nanoparticles. The role of the catalyst as a Lewis acid is promoting the reactions with the increase in the electrophilicity of the carbonyl and double band groups. To investigate the reusability of the catalyst, the model study was repeated using recovered cobalt oxide nanoparticles. The results showed that the nanocatalyst could be reused for five times with a minimal loss of its activity. Conclusion: We have developed an efficient and environmentally friendly method for the synthesis of some tetrasubstituted imidazoles via three-component reaction of benzil, primary amines, ammonium acetate and various aldehydes using Co3O4 NPs. The present approach suggests different benefits such as: excellent yields, short reaction times, simple workup procedure and recyclability of the magnetic nanocatalyst. The prepared 1,2,4,5-tetrasubstituted imidazoles revealed high antibacterial activities and can be useful in many biomedical applications.

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