1664-52-4Relevant academic research and scientific papers
Amide Bond Formation via the Rearrangement of Nitrile Imines Derived from N-2-Nitrophenyl Hydrazonyl Bromides
Boyle, Mhairi,Livingstone, Keith,Henry, Martyn C.,Elwood, Jessica M. L.,Lopez-Fernandez, J. Daniel,Jamieson, Craig
, p. 334 - 338 (2022/01/20)
We report how the rearrangement of highly reactive nitrile imines derived from N-2-nitrophenyl hydrazonyl bromides can be harnessed for the facile construction of amide bonds. This amidation reaction was found to be widely applicable to the synthesis of primary, secondary, and tertiary amides and was used as the key step in the synthesis of the lipid-lowering agent bezafibrate. The orthogonality and functional group tolerance of this approach was exemplified by the N-acylation of unprotected amino acids.
Water-removable ynamide coupling reagent for racemization-free syntheses of peptides, amides, and esters
Liu, Tao,Zhang, Xue,Peng, Zejun,Zhao, Junfeng
supporting information, p. 9916 - 9921 (2021/12/24)
A novel ynamide coupling reagent, the by-product of which can be removed by water, was reported. It promotes the direct coupling between carboxylic acids and amines, alcohols or thiols to provide amides, peptides, esters and thioesters, respectively. No detectable racemization was observed for all the coupling reactions of carboxylic acids containing an α-chiral center. Importantly, a simple acidic aqueous work-up removed the by-product readily to afford pure coupling products in good to excellent yields without the use of column chromatography, thus making this method more environmentally benign, user friendly and cost-effective. The robustness of the water-removable ynamide coupling reagent was further exemplified by the racemization/epimerization-free synthesis of carfilzomib, in which no column chromatography purification was involved for the entire 12-step synthesis.
Mechanochemical catalytic transfer hydrogenation of aromatic nitro derivatives
Portada, Tomislav,Margeti?, Davor,?trukil, Vjekoslav
supporting information, (2018/12/11)
Mechanochemical ball milling catalytic transfer hydrogenation (CTH) of aromatic nitro compounds using readily available and cheap ammonium formate as the hydrogen source is demonstrated as a simple, facile and clean approach for the synthesis of substituted anilines and selected pharmaceutically relevant compounds. The scope of mechanochemical CTH is broad, as the reduction conditions tolerate various functionalities, for example nitro, amino, hydroxy, carbonyl, amide, urea, amino acid and heterocyclic. The presented methodology was also successfully integrated with other types of chemical reactions previously carried out mechanochemically, such as amide bond formation by coupling amines with acyl chlorides or anhydrides and click-type coupling reactions between amines and iso(thio)cyanates. In this way, we showed that active pharmaceutical ingredients Procainamide and Paracetamol could be synthesized from the respective nitro-precursors on milligram and gram scale in excellent isolated yields.
Tetramethyl Orthosilicate (TMOS) as a Reagent for Direct Amidation of Carboxylic Acids
Braddock, D. Christopher,Lickiss, Paul D.,Rowley, Ben C.,Pugh, David,Purnomo, Teresa,Santhakumar, Gajan,Fussell, Steven J.
supporting information, p. 950 - 953 (2018/02/23)
Tetramethyl orthosilicate (TMOS) is shown to be an effective reagent for direct amidation of aliphatic and aromatic carboxylic acids with amines and anilines. The amide products are obtained in good to quantitative yields in pure form directly after workup without the need for any further purification. A silyl ester as the putative activated intermediate is observed by NMR methods. Amidations on a 1 mol scale are demonstrated with a favorable process mass intensity.
Method and using tracer charged ion channel
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Paragraph 0464; 0466; 0467-0469, (2018/08/20)
The invention provides compounds, compositions, methods, and kits for the treatment of pain, itch, and neurogenic inflammation.
ORGANIC REACTIONS CARRIED OUT IN AQUEOUS SOLUTION IN THE PRESENCE OF A HYDROXYALKYL(ALKYL)CELLULOSE OR AN ALKYLCELLULOSE
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Page/Page column 244; 245, (2017/08/21)
The present invention relates to a method of carrying out an organic reaction in aqueous solution in the presence of a hydroxyalkyl(alkyl)cellulose or an alkylcellulose.
Sulphuric acid immobilized on silica gel (H2SO4-SiO2) as an eco-friendly catalyst for transamidation
Rasheed,Rao, D. Nageswar,Reddy, A. Siva,Shankar, Ravi,Das, Parthasarathi
, p. 10567 - 10574 (2015/02/05)
A novel method of transamidation of carboxamides with amines by using catalytic amounts of H2SO4-SiO2 has been developed under solvent free conditions. The transamidation is compatible with a wide range of aromatic, heteroaromatic, aliphatic, cyclic/acyclic primary or secondary amines. The metal/solvent-free conditions represent a significant improvement over other existing methods as the reaction can be performed in open air conditions and no column purification is required. The versatility of this methodology was further demonstrated by synthesizing the commercially available drug procainamide.
Ammonium nitrate: A biodegradable and efficient catalyst for the direct amidation of esters under solvent-free conditions
Ramesh, Perla,Fadnavis, Nitin W.
supporting information, p. 138 - 140 (2015/02/19)
A simple, metal-free, and environment-friendly procedure is developed for the direct conversion of esters to amides using ammonium nitrate as a catalyst under solvent-free conditions. Aryls, heteroaryls, and aliphatic esters are easily converted to the corresponding amides in excellent isolated yields (85-99%). An enantiopure ester and amine were both shown to react without racemization. The methodology has been successfully applied to preparation of procainamide.
Direct amide synthesis from equimolar amounts of carboxylic acid and amine catalyzed by mesoporous silica SBA-15
Tamura, Mizuki,Murase, Daisuke,Komura, Kenichi
supporting information, p. 769 - 776 (2015/03/14)
Direct amide synthesis from equimolar amounts of carboxylic acid and amine using mesoporous silica as a versatile heterogeneous catalyst is reported.
Chemoselective reductions of nitroaromatics in water at room temperature
Kelly, Sean M.,Lipshutz, Bruce H.
supporting information, p. 98 - 101 (2014/01/23)
A robust and green protocol for the reduction of functionalized nitroarenes to the corresponding primary amines has been developed. It relies on inexpensive zinc dust in water containing nanomicelles derived from the commercially available designer surfactant TPGS-750-M. This mild process takes place at room temperature and tolerates a wide range of functionalities. Highly selective reductions can also be achieved in the presence of common protecting groups.
