Amides Organic Syntheses procedures

The reaction of 1,2-dicarbonyl compounds with amidrazones is the best method for the synthesis of alkyl-, aryl-, or hetaryl-substituted 1,2,4-triazines 1, in particular, if the monomeric 1,2-dicarbonyl compound is added to a solution of the free amidrazone or of the amidrazone hydrochloride in the presence of exactly one mole of base and stirred at room temperature for 24 hours.84 1,2,4-Triazinecarboxylates can also be prepared by this method an organic synthesis procedure is available.110 No limitation to this method has yet been reported, except that it is. of course, preferable for the dione to be symmetrical. The first step of the reaction, the condensation of the hydrazono group of the amidrazone with one carbonyl group is fast, but the second step, the condensation of the amide group with the second carbonyl group is often slow. As a consequence, the intermediate azine has been isolated in a few cases.111113... 

Amide and electron-poor aniline nucleophiles have also been employed in heteroaryl halide amination reactions. For example, an organic synthesis procedure was recently reported for the synthesis of ethyl 4-[(6-chloropyridin-3-yl)amino] benzoate via Ai-arylation of ethyl 4-aminobenzoate with 2-chloro-4-iodopyridine (Eq. 32) [220]. Beletskaya has illustrated that bromoindole derivatives can be coupled with amides utilizing either Xantphos or 3,5-(Cp3)2Xantphos (22) as the ligand in good yield (Eq. 33) [169]. 

The hydrolysis of a hindered amide can often be difficult. V. Bavetsias of the Cancer Research UK Laboratory in Surrey reports (Tetrahedron Lett. 2004, 45, 5643) that mcthanolic Fe(NO,),9H,0 will smoothly hydrolyze pivalamides such as 1 at room temperature. If this proves to be a general procedure for hindered amides, it will be a welcome addition to the armamentarium of organic synthesis. 

Acid amide-triphenylphosphine dihalide adducts (4) have found wide application in organic synthesis. - Synthetic equivalents are adducts (5) from acid amides and triphenylphosphine/CCU, which are prepared in situ from the educts. - With these reagents the following transformations have been performed dehydration of amides or aldoximes to nitriles, preparation of isonitriles from secondary form-amides, preparation of imidoyl halides from amides or acylhydrazines and preparation of ketene imines from amides. Using polymer-supported triphenylphosphine the work-up procedure is much easier to achieve. Triphenylphosphine can be replaced by tris(dialkylamino)phosphines. - Instead of CCI4 hexa-chloroethane, hexabromoethane or l,l,2,2-tetrabromo-l,2-dichloroethane can be used " the adducts thus formed are assumed to be more effective than those from the triphenylphosphine/CCU system. 

Dibutyltin oxide is the best source of tin for the Otera transesterification catalysts (eq 12) which have found wide use in organic synthesis. DBTO has also been used as a catalyst for hydrolysis of amides in very sensitive molecules, where other procedures have failed. ... 

The synthesis of sulfosuccinate esters—either monoesters or diesters—or the corresponding amides is usually done in a two-step procedure. In both cases, the MA is reacted in the first step with organic alcohol, organic amine, or (in the case of monoesters) with other suitable organic reactants that bear hydroxyl (or even protic) groups in the second step sulfation of the maleic ester takes place. 

The insertion of unsaturated molecules into metal-carbon bonds is a critically important step in many transition-metal catalyzed organic transformations. The difference in insertion propensity of carbon-carbon and carbon-nitrogen multiple bonds can be attributed to the coordination characteristics of the respective molecules. The difficulty in achieving a to it isomerization may be the reason for the paucity of imine insertions. The synthesis of amides by the insertion of imines into palladium(II)-acyl bonds is the first direct observation of the insertion of imines into bonds between transition metals and carbon (see Scheme 7). The alternating copolymerization of imines with carbon monoxide (in which the insertion of the imine into palladium-acyl bonds would be the key step in the chain growth sequence), if successful, should constitute a new procedure for the synthesis of polypeptides (see Scheme 7).348... 

For a carboxylic acid and an amine to form an amide, the carboxylic acid usually must be activated that is, it must be converted to a more reactive functional group. Conversion to an acyl chloride is a common way to accomplish this for normal organic reactions (see Chapter 19). However, acyl chlorides are quite reactive and do not give high enough yields in peptide synthesis because of side reactions. Therefore, milder procedures for forming the amide bond are usually employed. In one method the carboxylic acid is reacted with ethyl chloroformate (a half acyl chloride, half ester of carbonic acid) to produce an anhydride. Treatment of this anhydride with an amine results in the formation of an amide ... 

Solubility insol H2O sol all common organic solvents. Preparative Methods ligand (1) and related C2-symmetric bisox-azolines are readily prepared from chiral p-amino alcohols using standard methods for the synthesis of 2-oxazolines. This is exemplified by the simple three-step procedure shown in eq 1, involving amide formation, conversion of... 

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