Primary amines and amides

The reaction of chlorodiphenoxymethane with dimethylamine yields the amide acetal (459 equation 214). Dialkoxymethyl groups can be transferred by means of dialkoxyalkyltriethylammonium tetraflu-oroborate (460 equation 215) to primary amines and amides, amidines, secondary amines and amides once or twice to give amide acetals (461) and (462) Azodiazoles, e.g. (463) and (464) (Scheme 85), add to ketene dimethylacetal to give lactam acetals. ... 

The Rh" acetate catalysed decomposition of dimethyl a-diazobenzylpl-ospho-nate (204) in the presence of primary amines and amides offers a simple route to the corresponding a-aminophosphonates. 1-Aminocycloalkylphosphonates 205 have been synthesised from the corresponding cycloalkylphosphonate via electrophilic azidation of the phosphonate carbanion followed by catalytic hydrogenation. ... 

Diazotization with NaNO in trifluoroacetic acid permits the use of both deactivated and insoluble primary amines and amides which may be unreactive by the classical method. E Solid NaN02 added portionwise with stirring over 5 min to an ice-cooled soln. of ethyl 4-amino-2,3,5,6-tetrafluorocinnamate in trifluoroacetic acid, the mixture treated with NaN3 over a further 5 min, and stirring continued for a further 10 min ethyl 4-azido-2,3,5,6-tetrafluorocinnamate. Y 87%. F.e., Sandmeyer conversion (ar. chlorides), and isolation of carboxylic acids from amides s. K. Kanakara-jan et al., Synthesis 1988, 566-8. 

NH2 bending Intensity strong to medium In conjunction with bands in the 3300 cm region, this band is often used to characterize primary amines and amides. 

Other fairly recent commercial products, poly(vinyl amine) and poly(vinyl amine vinyl alcohol), have addressed the need for primary amines and their selective reactivity. Prior efforts to synthesize poly(vinyl amine) have been limited because of the difficulty hydrolyzing the intermediate polymers. The current product is prepared from /V-ethenylformamide (20) formed from the reaction of acetaldehyde and formamide. The vinyl amide is polymerized with a free-radical initiator, then hydrolyzed (eq. 7). 

Reactions with Amines and Amides. Hydroxybenzaldehydes undergo the normal reactions with aUphatic and aromatic primary amines to form imines and Schiff bases reaction with hydroxylamine gives an oxime, reaction with hydrazines gives hydrazones, and reactions with semicarbazide give semicarbazones. The reaction of 4-hydroxybenzaldehyde with hydroxylamine hydrochloride is a convenient method for the preparation of 4-cyanophenol (52,53). 

The primary products used are fatty acids with 12—18 carboa atoms and fatty alcohols, or esters of fatty acids such as the glycerides of rapeseed and lard oil (18). Eatty acid amines and amides are used ia metal working, particularly ia emulsions (18). 

The formation of 3-acylpyridinium compounds (59/) from primary amines and l-methoxybutene-3-one can be regarded as the enamine alkylation of a vinylogous amide followed by cyclization and loss of methanol and water. 

The formation of vinylogous amides from primary amines and -dicarbonyl compounds gives rise to hydrolyzable amine derivatives with greatly decreased nucleophilicity of the nitrogen function. Thus these derivatives have found some use as protecting groups in peptide syntheses 617-619). 

Nitriles are similar in some respects to carboxylic acids and are prepared either by SN2 reaction of an alkyl halide with cyanide ion or by dehydration of an amide. Nitriles undergo nucleophilic addition to the polar C=N bond in the same way that carbonyl compounds do. The most important reactions of nitriles are their hydrolysis to carboxylic acids, reduction to primary amines, and reaction with organometallic reagents to yield ketones. 

Primary and secondary amines and amides are first chlorinated at nitrogen by the chlorine released by the gradually decomposing calcium hypochlorite. Excess chlorine gas is then selectively reduced in the TLC layer by gaseous formaldehyde. The reactive chloramines produced in the chromatogram zones then oxidize iodide to iodine, which reacts with the starch to yield an intense blue iodine-starch inclusion complex. 

In classical organic chemistry, nltrosamlnes were considered only as the reaction products of secondary amines with an acidified solution of a nitrite salt or ester. Today, it is recognized that nitrosamines can be produced from primary, secondary, and tertiary amines, and nltrosamides from secondary amides. Douglass et al. (34) have published a good review of nitrosamine formation. For the purposes of this presentation, it will suffice to say that amine and amide precursors for nitrosation reactions to form N-nitroso compounds are indeed ubiquitous in our food supply, environment, and par-... 

Some other examples of metal-catalyzed substitutions are given in Scheme 11.10. Entries 1 to 3 are copper-catalyzed reactions. Entry 1 is an example of arylation of imidazole. Both dibenzylideneacetone and 1,10-phenanthroline were included as ligands and Cs2C03 was used as the base. Entry 2 is an example of amination by a primary amine. The ligand used in this case was (V,(V-diethyl sal icyl amide. These conditions proved effective for a variety of primary amines and aryl bromides with both ERG and EWG substituents. Entry 3 is an example of more classical conditions. The target structure is a phosphodiesterase inhibitor of a type used in treatment of asthma. Copper powder was used as the catalyst. 

The complete transformation of a racemic mixture into a single enantiomer is one of the challenging goals in asymmetric synthesis. We have developed metal-enzyme combinations for the dynamic kinetic resolution (DKR) of racemic primary amines. This procedure employs a heterogeneous palladium catalyst, Pd/A10(0H), as the racemization catalyst, Candida antarctica lipase B immobilized on acrylic resin (CAL-B) as the resolution catalyst and ethyl acetate or methoxymethylacetate as the acyl donor. Benzylic and aliphatic primary amines and one amino acid amide have been efficiently resolved with good yields (85—99 %) and high optical purities (97—99 %). The racemization catalyst was recyclable and could be reused for the DKR without activity loss at least 10 times. 

D. With Ammonia, Primary and Secondary Amines, and Amides... 

Wordy Over the past few years, we have encountered numerous examples of water as the perfect solvent. We observed this first in osmium-catalyzed dihydroxylation reactions and also in nucleophilic ring-opening reactions of epoxides. We also observed this in cycloaddition reactions and in most oxime ether, hydrazone, and aromatic heterocycle condensation processes.Finally, we observed it in formation reactions of an amide from a primary amine and an acid chloride using aqueous Schotten-Baumann conditions. ... 

Fig. 22 Possible reaction paths for the reaction between a-acidic isocyano amides (2 or 31), primary amines, and carbonyl components, including the Ag catalyzed formation of 2//-2-imidazolines (65)...

This process is similar to the formation of an ester by the action of an acid anhydride on an alcohol (described in the earlier section Acid anhydride plus an alcohol ). Half the acid anhydride forms the amide the other half is a leaving group. Ammonia, primary amines, and secondary amines react to produce amides. Figure 12-27 shows the industrial preparation of phenacetin by the reaction of an amine with an acid anhydride. The mechanism for this reaction is similar to the mechanism for the reaction of an acid chloride with an amine (refer to Figure 12-26). 

R.A. Reck, J. Am. Oil Chem. Soc. 56, 796A-801A (1979) . .Nitrogen Derivatives of Fatty Acids (Amides, Diamides, Nitriles, Primary Amines, and Oxides)". 

Nitroethane also has been utilized in place of primary amine or amide as a locking fragment in the template condensation reaction of amines and formaldehyde for the synthesis of macrocyclic complexes. For example, the square-planar Ni(II) complex of Lj was prepared by the reaction of Ni(en) +, formaldehyde, and nitroethane (17). 

---