Effects of electron donating (−CH3 and −OH) and electron withdrawing (−NO2) substituents on the corrosion inhibition efficiency of four glucosamine-based, substituted, pyrimidine-fused heterocycles (CARBs) on mild steel corrosion in 1 M HCl have been investigated using gravimetric, electrochemical, surface morphology (SEM, AFM, and EDX), and computational techniques. Gravimetric studies showed that protection performances of the compounds increase with increase in concentration. Both electron withdrawing (−NO2) and electron donating (−CH3 and −OH) groups were found to enhance the inhibition efficiency, but the effect is more pronounced with electron-donating substituents. The compounds were found to be cathodic-type inhibitors as inferred from the results of potentiodynamic polarization studies. EIS studies suggested that the studied compounds inhibit metallic corrosion by adsorbing on metallic surface. The adsorption of the inhibitor molecules on steel surface was further supported by SEM, AFM, and EDX a...

Adsorption Behavior of Glucosamine-Based, Pyrimidine-Fused Heterocycles as Green Corrosion Inhibitors for Mild Steel: Experimental and Theoretical Studies

With the growing interest in renewable energy and global warming, it is important to minimize the usage of hazardous chemicals in both academic and industrial research, elimination of waste, and possibly recycle them to obtain better results in greener fashion. The studies under the area of mechanochemistry which cover the grinding chemistry to ball milling, sonication, etc. are certainly of interest to the researchers working on the development of green methodologies. In this review, a collection of examples on recent developments in organic bond formation reactions like carbon–carbon (C–C), carbon–nitrogen (C–N), carbon–oxygen (C–O), carbon–halogen (C–X), etc. is documented. Mechanochemical syntheses of heterocyclic rings, multicomponent reactions and organometallic molecules including their catalytic applications are also highlighted.

https://www.beilstein-journals.org/bjoc/content/pdf/1860-5397-13-186.pdf

Mechanochemical synthesis of small organic molecules.

D-glucose derivatives of dihydropyrido-[2,3-d:6,5-d′]-dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone (GPHs) have been synthesized and investigated as corrosion inhibitors for mild steel in 1M HCl solution using gravimetric, electrochemical, surface, quantum chemical calculations and Monte Carlo simulations methods. The order of inhibition efficiencies is GPH-3 > GPH-2 > GPH-1. The results further showed that the inhibitor molecules with electron releasing (-OH, -OCH3) substituents exhibit higher efficiency than the parent molecule without any substituents. Polarization study suggests that the studied compounds are mixed-type but exhibited predominantly cathodic inhibitive effect. The adsorption of these compounds on mild steel surface obeyed the Langmuir adsorption isotherm. SEM, EDX and AFM analyses were used to confirm the inhibitive actions of the molecules on mild steel surface. Quantum chemical (QC) calculations and Monte Carlo (MC) simulations studies were undertaken to further corroborate the experimental results.

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Corrosion inhibition of mild steel in 1M HCl by D-glucose derivatives of dihydropyrido [2,3-d:6,5-d'] dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone.

Green recipes to quinoline: A review

Multicomponent Mannich reactions: General aspects, methodologies and applications

Being an attractive class of naturally occurring molecules with fascinating properties sugars and their derivatives have wide applications in different fields especially in drug discovery. Due to their highly diverse nature they play various important key roles in biological systems. In terms of providing both desirable structural diversity and compound libraries, multicomponent reactions (MCRs) are most efficient strategies. MCRs are widely employed by chemists to generate sugar based derivatives with significantly extended variations having various benefits to society. The advances in the synthesis of structurally diversified sugar based derivatives through new MCRs of the previous decade are reviewed.

Recent advances in multicomponent reactions involving carbohydrates

Tetrahydropyridines (THPDs) have been recognized as a major constituent of naturally occurring alkaloids. Being heterocyclic nitrogenous compounds, they therefore display robust biological and pharmacological profiles. In this context, they are fascinating synthetic targets in synthetic chemistry and as a consequence of this their synthesis through simple and convenient tactics has emerged as an important and challenging task. To meet such challenge, multicomponent reactions (MCRs) are employed as an excellent tool for achieving compounds containing complex diversity in single step and production of their vast libraries. This review represents the advancement made in the field of multicomponent synthesis of THPDs and their derivatives of the last few years.

Recent developments in multicomponent synthesis of structurally diversified tetrahydropyridines

Simple and efficient protocols have been developed for the synthesis of diversely functionalized dihydro-2-oxypyrroles and tetrahydropyridines. One-pot four-component reaction of dialkyl acetylenedicarboxylates, amines and formaldehyde in the presence of 2,6-pyridinedicarboxylic acid in methanol at room temperature provides dihydro-2-oxypyrroles. The combination of β-ketoesters, aromatic aldehydes and amines yielded tetrahydropyridine derivatives under the same reaction conditions. The salient features of these methods are mild reaction conditions, reduced reaction time, moderate to high yields, applicability to a broad range of substrates and no tedious column chromatographic separation.

Synthesis of functionalized dihydro-2-oxypyrroles and tetrahydropyridines using 2,6-pyridinedicarboxylic acid as an efficient and mild organocatalyst

The development of novel heterocyclic compounds from simple and easily accessible starting components is of significant importance in medicinal chemistry. Due to the presence of active chromophores and potent pharmacological activities, nitroketene N,S-acetals have emerged as a fascinating building block in organic synthesis. The synergistic skeleton of these acetals and the presence of electron-donating as well as electron-withdrawing groups lead to the generation of distinctive structural features and are highly useful for building diverse heterocyclic rings. This review highlights the preparation of different nitroketene N,S-acetals and their applications in the synthesis of diverse heterocyclic compounds.

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NitroketeneN,S-acetals: synergistic building blocks for the synthesis of heterocycles

Efficient and Eco-Friendly One-Pot Synthesis of Functionalized Furan-2-one, Pyrrol-2-one, and Tetrahydropyridine Using Lemon Juice as a Biodegradable Catalyst

Sarfaraz Khan

Papers

Recent advances in multicomponent reactions involving carbohydrates

Recent developments in multicomponent synthesis of structurally diversified tetrahydropyridines

Synthesis of functionalized dihydro-2-oxypyrroles and tetrahydropyridines using 2,6-pyridinedicarboxylic acid as an efficient and mild organocatalyst

NitroketeneN,S-acetals: synergistic building blocks for the synthesis of heterocycles

Efficient and Eco-Friendly One-Pot Synthesis of Functionalized Furan-2-one, Pyrrol-2-one, and Tetrahydropyridine Using Lemon Juice as a Biodegradable Catalyst