3-Amino-2-methylquinazolin-4-(3H)-one Schiff Bases Synthesis – a Green Chemistry Approach – a Comparison of Microwave and Ultrasound Promoted Synthesis with Mechanosynthesis.

2020 ◽  
Vol 07 ◽  
Author(s):  
Mario Komar ◽  
Fran Prašnikar ◽  
Tatjana Gazivoda Kraljević ◽  
Krunoslav Aladić ◽  
Maja Molnar
Keyword(s):  
Mass Spectrometry ◽  
Green Chemistry ◽  
Schiff Bases ◽  
13C Nmr Spectroscopy ◽  
Synthetic Methods ◽  
Reaction Conditions ◽  
1H And 13C Nmr ◽  
Microwave Assisted ◽  
Ultrasound Assisted ◽  
High Yields

: A green chemistry methods are important modern pathways in synthetic chemistry with main advantages such as milder reaction conditions, shorter time and higher yields. A series of quinazolinone based Schiff bases (1−27) have been successfully synthesized by using green synthetic methods including microwave-assisted, ultrasound-assisted and mechanochemical synthesis, respectively. Desired compounds were prepared from 3-amino-2-methylquinazolin-4(3H)- one and substituted benzaldehydes with moderate to high yields (11−90%). Benzoxazinone and 3-amino-2- methylquinazolin-4(3H)-one, the precursors of Schiff bases, were prepared by microwave induced synthesis. The structures of all Schiff bases are confirmed by 1H and 13C NMR spectroscopy and mass spectrometry as well. A novelty of this research is the application and comparison of green chemistry methods in the synthesis of desired compounds are listed above. The simplicity of synthesis includes ethanol as solvent and no need for further purification.

An Unprecedented Cyano-Induced Sodium Nitrite-Catalyzed C(sp3)-H and C(sp2)-H Coupling Reaction

2018 ◽  
Vol 15 (7) ◽  
pp. 989-994 ◽  
Author(s):  
Ling Li ◽  
Bo Su ◽  
Yuxiu Liu ◽  
Qingmin Wang
Keyword(s):  
Sodium Nitrite ◽  
Oxidative Coupling ◽  
High Resolution Mass Spectrometry ◽  
Coupling Reaction ◽  
13C Nmr Spectroscopy ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
1H And 13C Nmr ◽  
Oxidative Coupling Reaction ◽  
Oxidative Coupling Reactions

Aim and Objective: During the investigation of sodium nitrite-catalyzed oxidative coupling reaction of aryls, an unprecedented C(sp2)-H and C(sp3)-H coupling of substituted 2-aryl acetonitrile was found. Materials and Methods: The structure of the coupled product was confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS), and comparison of its derivatives with known compounds. The effects of methoxy group in the benzene ring on the reaction were evaluated. Results: The optimized reaction conditions are summarized as follows: CF3SO3H/substrate = 1.5 equiv., NaNO2/substrate = 0.3 equiv., CH3CN as solvent. 2-(4-Methoxyphenyl)acetonitrile and 2-(3,4,5- trimethoxyphenyl)acetonitrile could also generate C(sp2)-H and C(sp3)-H coupling. The coupling reaction occurred as a typical radial mechanism. Conclusion: An unprecedented cyano-induced, NaNO2-catalyzed oxidative C(sp3)-H and C(sp2)-H coupling was reported. The reaction proceeded under very mild conditions, using O2 in the air as terminal oxidant. The unique oxidative manner might provide more inspiration for the development of intriguing oxidative coupling reactions.

scholarly journals (2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol

Molbank ◽  
10.3390/m1140 ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. M1140
Author(s):  
Jack Bennett ◽  
Paul Murphy
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
13C Nmr ◽  
Conjugate Addition ◽  
13C Nmr Spectroscopy ◽  
One Pot ◽  
1H And 13C Nmr ◽  
Esi Mass Spectrometry ◽  
The One

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.

scholarly journals Microwave Assisted Synthesis of 1,5-Benzothiazepines Using Greener Reaction Medium

2019 ◽  
Vol 31 (5) ◽  
pp. 993-996 ◽  
Author(s):  
Sanjay S. Kotalwar ◽  
Amol D. Kale ◽  
Ram B. Kohire ◽  
Vasant B. Jagrut
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Reaction Medium ◽  
Microwave Assisted Synthesis ◽  
Reaction Conditions ◽  
Renewable Sources ◽  
Microwave Assisted ◽  
High Yields

An efficient and eco-friendly synthesis of 1,5-benzothiazepines has been developed by the reaction of various 2-propen-1-ones with 2-aminothiophenol using microwave irradiation in greener reaction medium, glycerol. The clean reaction conditions, shorter reaction time, high yields and non-toxic, biodegradable reaction medium manufactured from renewable sources are unique features of this method.

scholarly journals Aliphatic Diacidic Long-Chain C16 Polyesters from 10,16-Dihydroxyhexadecanoic Acid Obtained from Tomato Residual Wastes

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1524 ◽  
Author(s):  
Arrieta-Baez ◽  
Hernández Ortíz ◽  
Terán ◽  
Torres ◽  
Gómez-Patiño
Keyword(s):  
Mass Spectrometry ◽  
Enzymatic Reaction ◽  
Reaction Conditions ◽  
1H And 13C Nmr ◽  
Force Microscopy ◽  
Langmuir Blodgett ◽  
Atomic Force ◽  
One Step ◽  
Long Chain ◽  
Polyester Film

10,16-dihydroxyhexadecanoic acid obtained from agroresidual tomato waste, was oxidized to produce 7-oxohexadecanedioic acid in good yield (>70%) and purified without oxidation side products in one step. Polycondensation with 1,8-octanediol, yielded the polyester (poly(ω-carboxyl PA-co-OD)) with Mw = 2155.15 and Mn = 1637.27. The best enzymatic reaction conditions to get the polyester were using lipase CAL-B (%-by-wt relative to monomer) in toluene as a solvent for 1 h at 60 °C. The poly(ω-carboxyl PA-co-OD) was characterized by 1H- and 13C-NMR, mass spectrometry (MALDI-TOF) and the polyester film formed with a Langmuir-Blodgett Trough was analyzed by means of spectroscopic ellipsometry and atomic force microscopy.

scholarly journals Screening of Natural Deep Eutectic Solvents for Green Synthesis of 2-methyl-3-substituted Quinazolinones and Microwave-Assisted Synthesis of 3-aryl Quinazolinones in Ethanol

2020 ◽  
Vol 92 (4) ◽  
pp. 511-517
Author(s):  
Mario Komar ◽  
Maja Molnar ◽  
Anastazija Konjarević
Keyword(s):  
Green Synthesis ◽  
Anthranilic Acid ◽  
Deep Eutectic Solvents ◽  
13C Nmr Spectroscopy ◽  
Microwave Assisted Synthesis ◽  
One Pot ◽  
1H And 13C Nmr ◽  
Microwave Assisted ◽  
Natural Deep Eutectic Solvents ◽  
Quinazolinone Derivatives

In this study, two fast and efficient protocols for green synthesis of 3-substituted quinazolinones were perfomed. A synthesis of 2-methyl-3-substituted quinazolinones was performed in natural deep eutectic solvents, while 3-aryl quinazolinones were obtained by using microwave assisted synthesis. Benzoxazinone, which was used as an intermediate in the synthesis of 2-methyl-3-substituted quinazolinones, was prepared conventionally from anthranilic acid and acetic anhydride. In order to find the most appropriate synthetic path, twenty natural deep eutectic solvents were applied as a solvent in these syntheses. Choline chloride:urea (1 : 2) was found to be the most efficient solvent and was further used in the synthesis of 2-methyl quinazolinone derivatives (2–12). 3-Aryl quinazolinones (13–17), on the other hand, were synthesized in one-pot microwave-assisted reaction of anthranilic acid, different amines and trimethyl orthoformate. All compounds were synthesized in good to excellent yields, characterized by LC-MS/MS spectrometry and 1H- and 13C-NMR spectroscopy.

scholarly journals Green Chemistry Approach for Efficient Synthesis of Schiff Bases of Isatin Derivatives and Evaluation of Their Antibacterial Activities

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jnyanaranjan Panda ◽  
V. Jagannath Patro ◽  
Biswa Mohan Sahoo ◽  
Jitendriya Mishra
Keyword(s):  
Green Chemistry ◽  
Schiff Bases ◽  
Reaction Times ◽  
Antibacterial Activities ◽  
Primary Amines ◽  
Microwave Assisted Synthesis ◽  
Azomethine Group ◽  
Microwave Assisted ◽  
Isatin Derivatives

Microwave-assisted organic synthesis, a green chemistry approach, is nowadays widely used in the drug synthesis. Microwave-assisted synthesis improves both throughput and turnaround time for medicinal chemists by offering the benefits of drastically reduced reaction times, increased yields, and pure products. Schiff bases are the important class of organic compounds due to their flexibility, and structural diversities due to the presence of azomethine group which is helpful for elucidating the mechanism of transformation and rasemination reaction in biological system. This novel compound could also act as valuable ligands for the development of new chemical entities. In the present work, some Schiff bases of Isatin derivatives was synthesized using microwave heating method. Schiff base of Isatin were synthesized by condensation of the keto group of Isatin with different aromatic primary amines. They were characterized by means of spectral data and subsequently subjected to the in vitro antibacterial activities against gram positive and gram negative strains of microbes. It was observed that the compound with electron withdrawing substituents exhibited good antibacterial activities against almost all the micro organisms.

scholarly journals Microwave-assisted Efficient Synthesis of Isatins and spiro-Thiadiazolines under Green Chemistry Protocol

2010 ◽  
Vol 2 (2) ◽  
pp. 322-329 ◽  
Author(s):  
M. M. Hossain ◽  
M. A. Foysal ◽  
M. Mahabub ◽  
Al- Amin
Keyword(s):  
Schiff Base ◽  
Green Chemistry ◽  
Schiff Bases ◽  
Aromatic Amines ◽  
Electrophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Efficient Synthesis ◽  
Microwave Assisted ◽  
Primary Aromatic Amines ◽  
Mw Irradiation

MW-assisted treatment of oximinoacetanilides obtained from substituted primary aromatic amines was carried out in conc. H2SO4 medium for 5-10 sec to give cyclic amides (isatins) through intramolecular cyclization by means of electrophilic aromatic substitution. Isatins reacted with thiosemicarbazide under MW-condition gave the corresponding Schiff-bases. The Schiff-bases undergo cyclization in presence of minimal Ac2O under MW-irradiation for 3-4 min to give the spiro-thiadiazoline acetyl derivatives in excellent yield. Keywords:  Microwave-synthesis; Isatins; Schiff-base; spiro-Thiadiazoline; Green chemistry. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  DOI: 10.3329/jsr.v2i2.3731               J. Sci. Res. 2 (2), 322-329 (2010)  

A clean, simple and efficient synthesis of trans-[3-(aryl)-2,3-dihydrofuro[3,2-h] quinolin-2-yl]-(4-chlorophenyl)methanones

2017 ◽  
Vol 41 (7) ◽  
pp. 380-383
Author(s):  
Maryam Salari ◽  
Alireza Hassanabadi ◽  
Mohammad H. Mosslemin
Keyword(s):  
Reaction Time ◽  
Green Chemistry ◽  
Aromatic Aldehyde ◽  
Efficient Method ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Short Reaction Time ◽  
High Yields

We report a green and efficient method for the synthesis of trans-[3-(aryl)-2,3-dihydrofuro[3,2- h]quinolin-2-yl]-(4-chlorophenyl) methanones from the condensation of 2-[2-(4-chlorophenyl)-2-oxoethyl)]isoquinolinium bromide with 8-hydroxyquinoline and an aromatic aldehyde in the presence of catalytic amounts of choline hydroxide in water at reflux conditions. This new protocol employing choline hydroxide, which is a green and inexpensive catalyst, offers advantages such as mild reaction conditions, short reaction time, high yields and does not involve any hazardous solvent. Therefore, this procedure can be classified as green chemistry.

scholarly journals N-[2-(1H-Indol-3-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)ethyl]-4-methylbenzenesulfonamide

Molbank ◽  
10.3390/m1008 ◽  
2018 ◽  
Vol 2018 (3) ◽  
pp. M1008
Author(s):  
Nikil Purushotham ◽  
Boja Poojary
Keyword(s):  
Mass Spectrometry ◽  
Mycobacterium Tuberculosis ◽  
Potassium Hydroxide ◽  
Inhibitory Action ◽  
13C Nmr Spectroscopy ◽  
Enoyl Reductase ◽  
1H And 13C Nmr ◽  
Ft Ir ◽  
Non Covalent Interactions ◽  
Covalent Interactions

N-[1-Hydrazinyl-3-(1H-indol-3-yl)-1-oxopropan-2-yl]-4-methylbenzenesulfonamide (1) on cyclization with carbon disulfide in ethanolic potassium hydroxide affords N-[2-(1H-indol-3-yl)-1-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)ethyl]-4-methylbenzenesulfonamide (2) in 84% yield. The structure of compound 2 was supported by mass spectrometry, FT-IR and 1H- and 13C-NMR spectroscopy. To investigate the potential of compound 2 to act as antitubercular agent, it was docked against the enoyl reductase (InhA) enzyme of Mycobacterium tuberculosis. The docking pose and non-covalent interactions gave insights on its plausible inhibitory action.

L-Proline-Catalyzed Synthesis of Amino Thiazoles

2015 ◽  
Vol 729 ◽  
pp. 79-82
Author(s):  
Zhi Jie Li ◽  
Dong Ming Lu ◽  
Li Guo ◽  
Qing Le Zeng
Keyword(s):  
Transition Metal ◽  
Synthetic Methods ◽  
Environment Pollution ◽  
Reaction Conditions ◽  
High Yields

An L-proline-catalyzed synthesis of amino thiazoles is described here. Amides and 2-mercapto thiazoles were used as the starting reagents. Various reaction conditions were screened, and the scope of various amides and 2-mercapto thiazoles has been examined. Most of the substrates gave high yields. Compared with traditional synthetic methods with transition metal as catalyst, this protocol uses organocatalyst L-proline. It will reduce environment pollution and save the synthetic cost.

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