Urea as an ammonia surrogate in the Hantzsch’s synthesis of polyhydroquinolines /1,4-dihydropyridines under green reaction conditions

2020 ◽  
Vol 17 ◽  
Author(s):  
G. Dhananjaya ◽  
Akula Raghunadh ◽  
P. Mahesh Kumar ◽  
S. Pulla Reddy ◽  
V. Narayana Murthy ◽  
...  
Keyword(s):  
Ammonium Salt ◽  
Multicomponent Reaction ◽  
Sulphonic Acid ◽  
Ammonium Salts ◽  
Reaction Conditions ◽  
Wang Resin ◽  
Acidic Catalyst ◽  
Green Conditions

: Synthesis of polyhydroquinolines via Hantzsch’s multicomponent reaction (MCR) involves the use of a hygroscopic and moderately toxic ammonium salt as one of the key reactants. In our effort we have found urea as an effective ammonia surrogate when the MCR was performed in the presence of sulphonic acid functionalized Wang resin (Wang-OSO3H) as a polymeric and recoverable acidic catalyst under green conditions. Urea is relatively less hygroscopic / toxic than the commonly used ammonium salts used in this MCR. The methodology afforded a range of polyhydroquinolines in good yields. Depending on the nature of reaction conditions employed the MCR afforded Biginelli product or 1,4-DHPs when the use of 1,3-diketone was omitted.

An Efficient Synthesis of 2-Substituted Quinazolin-4(3H)-ones by Using Recyclable Wang Resin Supported Sulfonic Acid Catalyst

2020 ◽  
Vol 17 ◽  
Author(s):  
Kalyani K. ◽  
Srinivasa Reddy Kallam
Keyword(s):  
Sulfonic Acid ◽  
Functional Group ◽  
Acid Catalyst ◽  
Sulphonic Acid ◽  
Isatoic Anhydride ◽  
Efficient Synthesis ◽  
Wang Resin ◽  
Polymer Supported ◽  
High Yields

Abstract:: An efficient synthesis of 2-substituted Quinazolin-4(3H)-ones has been developed from isatoic anhydride with various amidoximes by using recyclable polymer supported sulphonic acid catalyst. Excellent functional group compatibil-ity and high yields are the important features of this protocol.

Cinchona alkaloid-based chiral catalysts act as highly efficient multifunctional organocatalysts for the asymmetric conjugate addition of malonates to nitroolefins

2015 ◽  
Vol 13 (40) ◽  
pp. 10216-10225 ◽  
Author(s):  
Veeramanoharan Ashokkumar ◽  
Ayyanar Siva
Keyword(s):  
Michael Addition ◽  
Quaternary Ammonium ◽  
Conjugate Addition ◽  
Quaternary Ammonium Salts ◽  
Cinchona Alkaloid ◽  
Ammonium Salts ◽  
Addition Reactions ◽  
Chiral Catalysts ◽  
Reaction Conditions ◽  
Highly Efficient

New pentaerythritol tetrabromide based chiral quaternary ammonium salts have been prepared and used as organocatalysts for enantioselective Michael addition reactions between various nitroolefins and Michael donors under mild reaction conditions with very good chemical yields and ee's.

scholarly journals Design of chiral urea-quaternary ammonium salt hybrid catalysts for asymmetric reactions of glycine Schiff bases

RSC Advances ◽  
2015 ◽  
Vol 5 (96) ◽  
pp. 78941-78949 ◽  
Author(s):  
Maximilian Tiffner ◽  
Johanna Novacek ◽  
Alfonso Busillo ◽  
Katharina Gratzer ◽  
Antonio Massa ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Ammonium Salt ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salt ◽  
Quaternary Ammonium Salts ◽  
Asymmetric Reactions ◽  
Ammonium Salts ◽  
Hybrid Catalysts

Bifunctional chiral urea-containing quaternary ammonium salts can be straightforwardly synthesised and systematically fine-tuned for asymmetric reactions of glycine Schiff bases.

Thermodynamic Derivations of Various Ammonium Salt Deposition Equations Common to the Refining Industry

CORROSION ◽  
10.5006/2855 ◽  
2018 ◽  
Vol 74 (10) ◽  
pp. 1158-1163 ◽  
Author(s):  
Brian R. Munson ◽  
Michael S. Cayard
Keyword(s):  
Ammonium Salt ◽  
Heat Exchangers ◽  
Equations Of State ◽  
Chemical Species ◽  
Refining Industry ◽  
Ammonium Salts ◽  
The Public ◽  
Salt Deposition ◽  
The Individual ◽  
Thermodynamic Equations

Ammonium salts represent a common problem for the refining industry. These saltslead to fouling of piping and heat exchangers resulting in loss of duty, underdeposit corrosionwhen wetted, and corrosive sour water solutionsonce sufficient water is available to dissociate these salts into solution. To properly manage fouling and corrosion associated with these salts, knowledge of the temperatures at which these salts will deposit is critical. In this age of process control, these temperatures can be predicted in real-time provided the salt deposition temperature relationships are known. The salt deposition equations for salts most often encountered in refining are not in the public domain. To close this gap, ammonium salt deposition equations were derived for NH4Cl, NH4HS, NH4Br, and NH4Fusing fundamental thermodynamic equations of state with published thermodynamic properties for the individual chemical species/reactions.

scholarly journals The Ugi-Smiles Reaction on Steroids: Discovery of Bioactive N,N-Disubstituted 3- Aminoestrones

2020 ◽  
Author(s):  
Cecilia Attorresi ◽  
Bruno Falcone ◽  
Evelyn Bonifazi ◽  
Gabriel Gola ◽  
Andrea Barquero ◽  
...  
Keyword(s):  
Multicomponent Reaction ◽  
Biological Activities ◽  
Steric Effects ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Antiviral Activities ◽  
Steroidal Derivatives

The Ugi-Smiles multicomponent reaction is a powerful tool for obtaining <i>N-</i>arylamines from acidic phenols and has been widely used for gaining access to structurally diverse scaffolds. In this work we demonstrate that this isocyanide-based coupling can be used for the straightforward and efficient synthesis of <i>N,N-</i>disubstituted 3-aminoestrones, steroidal derivatives that usually show interesting biological activities. In this sense, we analyzed the scope and limitations of the reaction when applied to aromatic nitrosteroids and found that the outcome is highly influenced by the steric effects imposed by the steroidal skeleton. After optimization of the reaction conditions a set of thirteen N-substituted 3-aminoestromes were obtained, some of them with interesting antiproliferative and antiviral activities.

scholarly journals 3-Bromopyridine-Heterogenized Phosphotungstic Acid for Efficient Trimerization of Biomass-Derived 5-Hydroxymethylfurfural with 2-Methylfuran to C21 Fuel Precursor

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yufei Xu ◽  
Zhaozhuo Yu ◽  
Hu Li ◽  
Song Yang
Keyword(s):  
Phosphotungstic Acid ◽  
Solvothermal Method ◽  
Reaction Pathway ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Acidic Catalyst ◽  
Carbon Compounds ◽  
Ft Ir ◽  
Long Chain

The production of long-chain carbon compounds (C9-C21) from biomass derivatives to alternate traditional fossil diesel is sustainable, eco-friendly, and potentially economic for modern industry. In this work, phosphotungstic acid heterogenized by 3-bromopyridine was achieved using a solvothermal method, which was demonstrated to be efficient for trimerization of biomass-derived 5-hydroxymethylfurfural (HMF) with 2-methylfuran (2-MF) to C21 fuel precursor (57.1% yield) under mild reaction conditions. The heterogeneous acidic catalyst could be reused for four consecutive cycles without obvious loss of activity, and different characterization techniques (e.g., XRD (X-ray diffraction), TG (thermogravimetric analysis), SEM (scanning electron microscope), FT-IR (Fourier transform infrared spectroscopy), and BET (Brunauer-Emmet-Teller)) were utilized to investigate the performance of the catalyst. In addition, a plausible reaction pathway was postulated, on the basis of results obtained by NMR (nuclear magnetic resonance) and GC-MS (gas chromatography-mass spectrometer). This strategy provides a facile and efficient approach to prepare a recyclable acidic catalyst for the production of diesel fuel precursor from biomass via controllable polymerization.

Synthesis of Several Sugar Acetates and their Structures Characterization

2012 ◽  
Vol 602-604 ◽  
pp. 1373-1378
Author(s):  
Jing Liang ◽  
Zhen Xing Cheng ◽  
Lian Yuan Wang ◽  
Hai Yan Zhu ◽  
Shi Gao ◽  
...  
Keyword(s):  
Reaction Time ◽  
Acetic Anhydride ◽  
Reaction Temperature ◽  
Soluble Starch ◽  
Degree Of Substitution ◽  
High Yield ◽  
Reaction Conditions ◽  
Alkaline Catalyst ◽  
Acetate Esters ◽  
Acidic Catalyst

Several acetate esters were synthesized by reacting sugars, i.e. glucose, soluble starch, and dextrin, with acetic anhydride in the presence of some catalysts. Their structures were confirmed by IR and MS. Influences of the reaction conditions, such as catalyst and its dosage, reaction time, reaction temperature and acetic anhydride content, on the value of degree of substitution (DS) and the yield for starch acetates had also been investigated. Results showed that glucose could be easily completely acetylated; acidic catalyst tended to form a configuration of α-glucose penta-acetate (α-GPA), while alkaline catalyst β-GPA. However, soluble starch and dextrin were more difficult to be completely substituted by acetic anhydride. The DS value of soluble starch was below 2; for dextrin, its DS value could reach 2.3, close to the theoretical value of 3. An appropriate reaction temperature and reaction time were important for high yield as well as high DS value.

Transition Metal-free Approach for the Synthesis of 2-substituted Quinazolin-4(3H)-one via Anhydrous Magnesium Perchlorate

2020 ◽  
Vol 7 (2) ◽  
pp. 118-123
Author(s):  
Shweta Mishra ◽  
Debashree Das ◽  
Adarsh Sahu ◽  
Shailendra Patil ◽  
Ram Kishor Agarwal ◽  
...  
Keyword(s):  
Transition Metal ◽  
Aromatic Aldehydes ◽  
Magnesium Perchlorate ◽  
Reaction Conditions ◽  
Metal Free ◽  
Convenient Synthesis ◽  
Wide Availability ◽  
Ic50 Values ◽  
Antileishmanial Activities ◽  
Green Conditions

Background: A convenient and efficient methodology for the synthesis of quinazolin- 4(3H)-ones from simple and readily available 2-amino benzamides and aromatic aldehydes in ethanol using Magnesium perchlorate are being reported in the present study. Good to excellent isolated yields (68-95%) of the corresponding 2-substituted quinazolinones were obtained under mild reaction conditions with excellent functional group tolerance. The affordability of the catalyst, the wide availability of the starting materials, transition metal free synthesis and the simplicity of the procedure renders the present methodology useful in organic synthesis. Objective: A maneuver methodology developed for the synthesis of quinazolin-4(3H)-ones via using Magnesium perchlorate from 2-amino benzamides and aromatic aldehydes in ethanol. Methods: 10% mol anhydrous Magnesium perchlorate in presence of ethanol give to simply rapid formation of Quinazolin-4(3H)-ones from 1 mole of 2-amino benzamides and 1 mole of aromatic aldehydes. Results: Screening results of Anti-leishmanial showed that out of the synthesized series of 12 compounds, compounds 3c, 3d, 3g, 3h and 3i showed significant antileishmanial activities (L. donavani) with IC50 values 8.39, 9.37, 9.43, 7.1 and 8.7 μM. Conclusion: In summary, we have developed convenient synthesis of quinazolin-4(3H)-one, from simple and easily available precursor employing anhydrous Mg(ClO4)2 under green conditions.

Synthesis of Quaternary Ammonium Salt Cationic Surfactant with Long-Chain Alkyl and Epoxy Groups

2012 ◽  
Vol 554-556 ◽  
pp. 864-867 ◽  
Author(s):  
Zong Cheng Miao ◽  
Fang Wang ◽  
Deng Deng ◽  
Lei Wang ◽  
Jian Zhou Yang
Keyword(s):  
Cationic Surfactant ◽  
Ammonium Salt ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salt ◽  
Traditional Method ◽  
Raw Materials ◽  
Reaction Conditions ◽  
Important Intermediate ◽  
Epoxy Groups ◽  
Long Chain

The quaternary ammonium salt cationic surfactant with long-chain alkyl and epoxy groups is very important intermediate product to synthesis novel functional surfactants. In this paper, a kind of quaternary ammonium salt cationic surfactant with long-chain alkyl and epoxy groups was synthesized by traditional method with epichlorohydrin and N-octadecyldimethylamine as raw materials. During the synthesis, the best reaction conditions have been obtained, that the reaction temperature is 35 °C, the reaction time is 4 h and the best mol ratio of epichlorohydrin to timethylamine is 5:1. In addition, the synthesized intermediate with long-chain alkyl and epoxy groups plays a very important roles in the development of cationic surfactant.

An efficient catalyst-free chemoselective multicomponent reaction for the synthesis of pyrimidine functionalized pyrrolo-annelated derivatives

RSC Advances ◽  
2015 ◽  
Vol 5 (31) ◽  
pp. 24327-24335 ◽  
Author(s):  
Yuvaraj Dommaraju ◽  
Somadrita Borthakur ◽  
Nimmakuri Rajesh ◽  
Dipak Prajapati
Keyword(s):  
Multicomponent Reaction ◽  
Reaction Conditions ◽  
One Pot ◽  
Efficient Catalyst ◽  
Catalyst Free ◽  
High Yields

An efficient catalyst-free, one-pot multicomponent reaction has been developed for the synthesis of pyrimidine functionalized pyrrolo-annelated derivatives. The method offers easy and column free separation, mild reaction conditions and high yields.

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