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Organic Synthesis
Published in Suresh C. Ameta, Rakshit Ameta, Garima Ameta, Sonochemistry, 2018
Chetna Ameta, Arpit Kumar Pathak, P. B. Punjabi
Ghadami and Jafari (2015) carried out an efficient synthesis of Mannich bases by sonication in sodium dodecyl sulphate micellar media by Mannich reaction of aldehydes, aromatic amines, and acetophenone derivatives or cyclohexanone. The sonication of biphasic systems was performed at 37 kHz, 300 W, under neutral conditions. It was observed that the reaction can be carried out readily under milder conditions. The precipitated solid Mannich product was recovered by simple filtration without using any organic solvent.
Name Reactions
Published in Benny K.G. Theng, Clay Mineral Catalysis of Organic Reactions, 2018
The Mannich reaction describes the three-component amino alkylation from amine, formaldehyde, and a compound with an acidic methylene group. The final product, a β-amino-carbonyl compound, is referred to as a Mannich base.
γ-aminobutyric acid and collagen peptides as recyclable bifunctional biocatalysts for the solvent-free one-pot synthesis of 2-aminobenzothiazolomethyl-2-naphthols
Published in Green Chemistry Letters and Reviews, 2018
Maryam Fardpour, Ali Safari, Shahrzad Javanshir
Based on the above results and the previous reports, plausible mechanisms for these two methods are given in Schemes 2 and 3. The reaction mechanism for method A starts with the nucleophilic addition of the amine group of amino acid to the carbonyl group of aldehyde followed by dehydration which leads to the formation of iminium ion A that undergoes reaction with 2-naphtol to give the Mannich base B. Intermediate B is in equilibrium with its zwitterion form C that undergoes amino acid elimination to form the ortho-quinone methide D. Finally, o-QM D readily reacts with 2-aminobenzothiazole to produce the desired product 5 and GABA goes back to the catalytic cycle as an active catalyst (Scheme 2). The proposed mechanism for method B is depicted in Scheme 3.
Transition metal complexes incorporating lawsone: a review
Published in Journal of Coordination Chemistry, 2022
Freeda Selva Sheela Selvaraj, Michael Samuel, Arunsunai Kumar Karuppiah, Natarajan Raman
Mannich reaction paves the way for synthesis of more derivatives of lawsone. Mannich bases of lawsone are prepared by the treatment of lawsone dissolved in ethanol with an amine followed by addition of an aldehyde under stirring at room temperature for 12 h. To prepare the metal complex, the obtained Mannich base ligand suspended in methanol was treated with methanolic solution of the metal salt in the presence of triethyl amine under stirring for 12 h. The precipitate obtained was filtered, washed with methanol and dried under vacuum. Many Mannich base complexes (16-19) (Figure 7) have been prepared using this procedure with slight modifications [28, 57–63].