Amidation, of aromatic

Amidation of aromatic rings with hydroxamic acids... 

Dermer and Edmison 54>, and a somewhat more refined approach was taken by Heacock and Edmison 55> whose results on the benzenesulphon-amidation of aromatic substrates are given in Table 1. 

In company with manganese porphyrin complex, ruthenium porphyrins have already shown great catalytic activity in the intermolecular amidation of saturated G-H bonds. However, examples of amidation of aromatic... 

Table 2 [Ru"(TTP)(CO)]-catalyzed amidation of aromatic heterocycles with Phl=NTs...

Assignments for C—H out-of-plane bending bands in the spectra of substituted benzenes appear in the chart of characteristic group absorptions (Appendix C). These assignments are usually reliable for alkyl-substituted benzenes, but caution must be observed in the interpretation of spectra when polar groups are attached directly to the ring, for example, in nitroben-zenes, aromatic acids, and esters or amides of aromatic acids. 

Intramolecular acylation 1-21 Intramolecular amidation of aromatic rings... 

Palladium-Catalyzed Amidation of Aromatic and Vinylic Halides ... 

The Photosensitized Amidation of Aromatic Hydrocarbons. Tetrahedron Letters No. 2, 77 (1963). 

Pyridine-4-thiocarboxamide is reduced in two, two-electron steps in acidic medium at the potential of the second wave, reduction gives 4-aminomethylpyridine. The product of reduction at the first wave is believed to be the aminothiol [126]. These three cases show that the preparative outcome of an amide reduction is strongly dependent on the substituents at the amide group and that the changes manifest themselves in the chemical step [Eq. (32)]. For the amides of aromatic carboxylic acids, the reduction potential may be gleaned from a comprehensive compilation [127]. 

Substituted amides of aromatic carboxylic acids or of sulfonic acids are prepared by the Schotten-Baumann technique the acid chloride is added to the amine in the presence of a base, either aqueous sodium hydroxide or pyridine. For example ... 

Preparation of a-amino acid amides of aromatic amines (111) is easily conducted as a one-pot procedure by the modified Curtius reaction of aromatic carboxylic acids with DPPA, followed by reaction with iV-protected a-amino acids (equation 44). By this method, -t-butoxycarbonyl-L-leucine p-nitroanilide, which serves as a substrate for leucine aminopeptidase after deblocking of its r-butoxycar-bonyl group, has been efficiently prepared from p-nitrobenzoic acid and -r-butoxycarbonyl-L-leucine. 

For the purpose of drug spectrocognition, acid amides of aromatic amines have to be subdivided into two largely different groups ... 

Substitutions and Displacements [1,904J Direct amidation of aromatic compounds can sometimes be achieved by reaction with a hydroxamic acid in PPA 48a... 

Within the last two decades, a number of chemical structures have been proposed as metal deactivators for polyolefins. These include carboxylic acid amides of aromatic mono- and di-carboxylic acids and N-substituted derivatives such as N,N -diphenyloxamide, cyclic amides such as barbituric acid, hydrazones and bishydrazones of aromatic aldehydes such as benzaldehyde and salicylaldehyde or of o-hydroxy-arylketones, hydrazides of aliphatic and aromatic mono- and di-carboxylic acids as well as N-acylated derivatives thereof, bisacylated hydrazine derivatives, polyhydrazides, and phosphorus acid ester of a thiobisphenol. An index of trade names and suppliers of a few commercial metal deactivators is given in Appendix A4. 

Oxidative amidation of aromatic aldehydes with amines. 

Leow reported the use of a phenazinium salt, either phenazine ethosulfate or saffanin O, as a photocatalyst for the aerobic oxidative amidation of aromatic aldehydes with secondary amines to prepare the corresponding amides in good to high yields (Scheme 62) (140L5812).This method provides access to a more ecologically safe, mild, and inexpensive generation of benzamides. 

Antilla and co-workers [141] have found that the Brpnsted acid 65 derived from R-VAPOL catalyzes efficiently the asymmetric amidation of aromatic iV-Boc imines to produce aminals (Scheme 11.53). Thus, a series of aromatic A-Boc imines react with different sulfonamides to afford the corresponding aminals in excellent yields (80-99%) and enantioselectivities (87-94% ee). When using o-toluenesulfonamide, due to steric factors, longer reaction times and lower enantioselectivity were obtained (50h, 73% ee). Unfortunately, the absolute configuration of the major enantiomer was not determined. 

Yu et al. [143] described the ortho amidation of aromatic and aliphatic oximes under C-H activation. Pd(OAc)2 as a catalyst in combination with Sequiv. of K2S20g as an oxidant was required for the amidation reaction (Scheme 13.98). 

Pyridines direct rhodium(III)-catalyzed C-H activation and amidation of aromatic systems using iV-OTs imides (Scheme 45) (13OL3706). 

Fragmentation Amides of aromatic acids exhibit maxima due to amide bond cleavage yielding the benzoyl ion, followed by decarbonylation (Am 28). 

Ley J.P., BUngs M., Paetz S., Krammer G.E., Bertram H.-J. New bitter-masking compounds hydroxylated benzoic acid amides of aromatic amines as structural analogues of homoeriodictyol. Journal of Agricultural and Food Chemistry, 54 8574-8579 (2006). 

Successful application of the reaction has also been made to the half-amides of aromatic dicarboxylic acids. For example, 2-carboxy-4,5-dichlorobenzamide is converted readily by the action of alkaline sodium hypochlorite to 4,5-dichloroanthranilic acid. ... 

Saberi D, Heydari A (2014) Oxidative amidation of aromatic aldehydes with amine hydrochloride salts catalyzed by silica-coated magnetic carbon nanotubes (MagCNTs Si02)-immobilized imine—Cu(I). Appl Oiganomet Chem 28(2) 101-108... 

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