Carboxylic acid amid amides

Hofmann s amine synthesis can be applied to both aliphatic and aromatic carboxylic acid amides, benzamide, C HsCONH, thus giving aniline, C4H5NH,. 

Amino groups bound to sulfur can be replaced by fluorine via diazotization. In contrast to carboxylic acid amides, fluorodediazoniation of aromatic sulfonamides IS readily accomplished to give sulfonyl fluorides in high yields [52, 7S (equation 16) Tetrazotization-fluorination of sulfanilamide can also be effected to give a 38% yield of p-fluorobenzenesulfonyl fluoride [52],... 

Bond-Huper [69JCS(C)2453] synthesis, no traces of the described high-melting dark red substance were found. Only tolane-2-carboxylic acid amide (yield 65%) was obtained—the white crystals with a melting temperature of 156-157°C— which coincided with the results of Castro et al. (66JOC4071). Thus, in conditions of acetylide synthesis, o-iodobenzamide forms no bicyclic product. 

Intramolecular addition of the amide group to the triple bond in pyrazoles is more difficult, and results in closure of the 5-lactam rather than the y-lactam ring. The reaction time of the 4-phenylethynylpyrazole-3-carboxylic acid amide under the same conditions is extended to 42 h (Scheme 129) (Table XXVII). The cyclization of l-methyl-4-phenylethynyl-l//-pyrazole-3-carboxylic acid amide, in which the acetylene substituent is located in the 7r-electron-rich position of the heterocycle, is the only one complete after 107 h (Scheme 130) (90IZV2089). 

TABLE XXVn. l-Methyl-l,6-dihydropyrazolo[3,4-c]pyridin-7-ones Prepared by Cyclization of Vicinal 4-(Alkyn- l-yl)pyrazole-5-carboxylic Acid Amides [90IZV2089]. 

Anhydrides are reduced with relative ease. McAlees and McCrindle 20) established the following increasing order of difficulty for various carbonyls acid chlorides > aldehydes, ketones > anhydrides > esters > carboxylic acids > amides. Reduction may proceed by 1,2-addilion of hydrogen or by cleavage of an oxygen-carbonyl bond. If 1,2-addition to the carbonyl occurs, as in the presence of strong protic acids over palladium, 1,1-diesters are formed by acylation 26). 

Many procedures for the formation of carboxylic acid amides are known in the literature. The most widely practiced method employs carboxylic acid chlorides as the electrophiles which react with the amine in the presence of an acid scavenger. Despite its wide scope, this protocol suffers from several drawbacks. Most notable are the limited stability of many acid chlorides and the need for hazardous reagents for their preparation (thionyl chloride, oxalyl chloride, phosgene etc.) which release corrosive and volatile by-products. Moreover, almost any other functional group in either reaction partner needs to be protected to ensure chemoselective amide formation.2 The procedure outlined above presents a convenient and catalytic alternative to this standard protocol. 

The tertiary amines 303 and the acid chlorides 304 (X = Cl) initially formed acylammonium salts 305, which underwent a von Braun type degradation by an attack of the nucleophilic chloride ion at the allyl system to give allyl chlorides 306/307 and carboxylic acid amide functions. 

Some pairs of functional groups such as alcohol, ester carboxylic acid, ester amine, amide and carboxylic acid, amide can be interconverted by simple reactions. When a member of these groups is the desired product or starting material, the other member should also be consulted in the text. 

Section 315 (Carboxylic Acid - Amide). Section 344 (Amide - Ester). 

Hydroxylation of long-chain carboxylic acids, amides, and alcohols—but not the esters or the corresponding alkanes—at the w-l, (0-2, and (o-3 positions by a soluble enzyme system from Bacillus megaterium (Miura and Fulco 1975 Narhi and Fulco 1986,1987). 

Alkylation of Aldehydes, Esters, Carboxylic Acids, Amides, and Nitriles... 

Cleavage of all the linkers described above provide a functional group (carboxylic acid, amide, amine, etc) at the anchoring position. Silyl-based handles 71,72, and 73 as well as germanium-based handle 74 insert a C-H bond at the anchoring position and are referred to as traceless (Fig. 15) [82-... 

In contrast to the reaction of benzamide and other carboxylic acid amides with lead tetraacetate, which has been said to proceed via an acyl nitrene intermediate 46>, methanesulphonamide and 2-biphenylsulphon-amide are completely inert towards this reagent 42>. 

The Alper group [163] reported on a highly efficient double carbohydroamination for the preparation of a-amino carboxylic acid amides 6/1-345, starting from aryl iodides and a primary amine 6/1-344, in usually high yield (Scheme 6/1.88) both, aryl iodides with electron-donating and electron-withdrawing groups can be used. 

The synthesis of nitriles from halides is valuable in medicinal chemistry because nitriles are flexible building blocks readily converted into carboxylic acids, amides, amines, or a variety of heterocycles, e. g. thiazoles, oxazolidones, triazoles, and tetrazoles. The importance of the tetrazole group in medicinal chemistry is easily understood if we consider that it is the most commonly used bioisostere of the carboxyl group. 

Isocyanates are quite reactive and they react with compounds which contain active hydrogen such as hydroxy, amine, carboxylic acids, amide, urea, etc. They can also undergo addition reaction ... 

Addition of HCN to acetone to form the cyanohydrin is still the main route to methyl methacrylate. Hydrocyanins can be converted to amino acids as well. The nitrile group can be easily converted to amines, carboxylic acids, amides, etc. Addition to aldehydes and activated alkenes can be done with simple base, but addition to unactivated alkenes requires a transition metal catalyst. The methods of HCN addition have been discussed by Brown [2],... 

CHIREX 3022 [N-l-[(l-naphthyl)ethyl]amido]indoline-2-carboxylic acid amide 179... 

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