Aliphatic acid amides table

Glycosyl imines from aliphatic aldehydes are sensitive to anomerization. However, the anomerization can be avoided by conducting the reactions at lower temperatures (-78 °C). Recrystallization of the crude products (methanol/water for aliphatic, heptane for aromatic compounds) gave the diastereomerically pure D-amino acid amides (Table 4.3). 

Mono-A-alkylation of the amides occurs under relatively mild liquiddiquid two-phase conditions (Table 5.10), using concentrated aqueous sodium or potassium hydroxide. Under soliddiquid conditions with sodium hydroxide-potassium carbonate or potassium hydroxide, or by using super-saturated aqueous potassium or sodium hydroxide, it is possible to control the reaction to obtain either the mono-or dialkylated derivatives f2-4]. Soliddiquid two-phase conditions also provide the most effective route to mono-AI-alkylalion of weakly acidic aliphatic amides, but it has been suggested that the procedure is not sufficiently selective for the monoalkylation of the more acidic amides [4],... 

For convenience of isolating the reaction product in a crystalline state, acid amides containing aromatic ring(s), i.e., acetanilide and benzanilide, were selected, and were allowed to react with AlMe3, AlEt3, or A1Bu 3. The reaction product could be obtained in a crystalline state by adding an aliphatic hydrocarbon such as iso-octane to the reaction mixture in toluene. The catalytic behavior of the isolated reaction products indicated that these products were the real active species of the catalyst system (36) (Table 2). 

The melting points of aliphatic and aromatic primary carboxylic acid amides and those of the corresponding xanthylamides are collected in Tables 10.27 and 10.28. 

The pure diastereomers of compounds 31 are obtained by recrystallization or flash chromatography (Scheme 21). The stereoselective synthesis of aliphatic, aromatic, branched-chain, and heteroaromatic amino acid amides has been demonstrated by using this methodology. Table 4.4 illustrates the wide scope of the reaction. 

Methyl-1,2-dihydroisoquinoline has been reacted8,66 with a variety of acid chlorides (Table III) the expected vinylogous amides (64) were isolated in most cases. 2-Benzyl-l,2-dihydroisoquinoline behaves similarly. The acylation reaction fails with simple aliphatic acid chlorides. Sometimes, the reaction of the enamine with the acid in the presence of dicyclohexylcarbodimide succeeds. The 1,2-dihydro-isoquinoline (65) also reacts with ethoxalyl chloride to yield 66.86... 

Activation of aliphatic and aromatic carboxylic acids with sulfuric acid derivatives yields amides (Table 3). Sulfuryl chloride fluoride and primary amines or chlorosulfonyl isocyanate and secondary amines are used as reaction partners. 

These pol)uners are not resistant to highly alkaline solutions of sodium hydroxide, concentrated sulfuric acid, alkaline solutions with pFI greater than 10, aliphatic, primary and aromatic amines, amides, and other alkaline organics, phenols, and acid halides. Table 3.11 provides the compatibility of halogenated polyesters with selected corrodents. Reference [1] provides a more comprehensive listing. 

The two main commercial polyamides are nylon 6,6, produced by condensation polymerization of HMD and adipic acid (see Table 7.1), and nylon 6, an AB-type polymer, which is produced from caprolactam. Other commercial polyamides include nylons 4,6, nylon 6,12 (which are AA- and BB-type polymers) and nylon 11 and nylon 12 (which are AB polymers made from linear aliphatic amino acids containing 11 and 12 carbons, respectively) [1]. Polyamides are also produced using monomers with aromatic, rather than aliphatic segments. Polyamides that contain 85% or more of the amide bonds attached to aromatic rings are called aramids. Commercial examples include poly(p-phenyleneterephthalamide) or Kevlar and poly(m-phenyleneisoterephthalamide) or Nomex [23]. 

DKR for the Synthesis of Esters, Amides and Acids Using Lipases Table 4.4 DKR of various aliphatic amines... 

Differences of <5 = 0.32-0.40 in the, 9F chemical shift for epimeric A -acylated Mosher derivatives of aliphatic a-amino acids, in particular alanine, as well as its amides and peptide derivatives, are sufficiently large to serve as a racemisation test23. However, high-field spectrometers are recommended to provide improved sensitivity (<0.5%). Table 19, representing analysis data taken at 376.5 MHz, can be found in Section 3.2.2.9. Analysis of absolute configuration of amino acids and amines can be more accurate using a modified Mosher method24. 

Triazenes have been prepared by the treatment of resin-bound aromatic diazonium salts with secondary amines (Figure 3.27). Regeneration of the amine can be effected by mild acidolysis (Entry 1, Table 3.23). Triazenes have been shown to be stable towards bases such as TBAF, potassium hydroxide, or potassium tert-butoxide [454], and under the conditions of the Heck reaction [455]. Primary amines cannot be linked to supports as triazenes because treatment of triazenes such as R-HN-N=N-Ar-Pol with acid leads to the release of aliphatic diazonium salts into solution [373]. Triazenes derived from primary amines can, however, be used for the preparation of amides and ureas (see Section 3.3.4),... 

Amidines and sulfonamides have also been used as linkers for primary or secondary aliphatic amines (Entries 4, 5, and 7, Table 3.23). These derivatives are stable under basic and acidic reaction conditions and can only be cleaved by strong nucleophiles. Phenylalanine amides can be hydrolyzed by treatment with certain enzymes (Entry 8, Table 3.23), and can therefore be used for linking amines to supports compatible with enzyme-mediated reactions (CPG, some polyacrylamides, macroporous polystyrene, etc.). 

Most C,H-acidic compounds can be condensed with aldehydes or ketones to yield alkenes. Some of these reactions have also been realized on insoluble supports, with either the C,H-acidic (nucleophilic) reactant or the electrophilic reactant linked to the support. Some illustrative examples are listed in Table 5.6. Polystyrene-bound malonic esters or amides, cyanoacetamides, nitroacetic ester [95], and 3-oxo esters undergo Knoevenagel condensation with aromatic or aliphatic aldehydes. Catalytic amounts of piperidine and heating are generally required, although reactive substrates can react at room temperature. 

Alternatively, sulfonamides can also be prepared by oxidation of sulfinamides with periodate (Entry 3, Table 8.8) or with MCPBA [125]. Polystyrene-bound sulfonyl chlorides, which can be prepared from polystyrene-bound sulfonic acids by treatment with PCI5, SOCI2 [126-129], CISO3H [130], or SO2CI2/PPI13 [131], react smoothly with amines to yield the corresponding sulfonamides (Entry 4, Table 8.8). Support-bound carbamates of primary aliphatic or aromatic amines can be N-sulfonylated in the presence of strong bases, and can therefore be used as backbone amide linkers for sulfonamides (Entries 5 and 6, Table 8.8). 

The esterification of support-bound carboxylic acids has not been investigated as thoroughly as the esterification of support-bound alcohols. Resin-bound activated acid derivatives that are well suited to the preparation of esters include O-acylisoureas (formed from acids and carbodiimides), acyl halides [23,226-228], and mixed anhydrides (Table 13.15). A-Acylurea formation does not compete with esterifications as efficiently as it does with the formation of amides from support-bound acids. Esters can also be prepared from carboxylic acids on insoluble supports by acid-catalyzed esterification [152,229]. Alternatively, support-bound carboxylic acids can be esteri-fied by O-alkylation, either with primary or secondary aliphatic alcohols under Mitsu-nobu conditions or with reactive alkyl halides or sulfonates (Table 13.15). 

Various approaches have been used to prepare pyrroles on insoluble supports (Figure 15.1). These include the condensation of a-halo ketones or nitroalkenes with enamines (Hantzsch pyrrole synthesis) and the decarboxylative condensation of N-acyl a-amino acids with alkynes (Table 15.3). The enamines required for the Hanztsch pyrrole synthesis are obtained by treating support-bound acetoacetamides with primary aliphatic amines. Unfortunately, 3-keto amides other than acetoacetamides are not readily accessible this imposes some limitations on the range of substituents that may be incorporated into the products. Pyrroles have also been prepared by the treatment of polystyrene-bound vinylsulfones with isonitriles such as Tosmic [28] and by the reaction of resin-bound sulfonic esters of a-hydroxy ketones with enamines [29]. 

A crude mixture of enzymes isolated from Rhodococcus sp. is used for selective hydrolysis of aromatic and aliphatic nitriles and dinitriles (117). Nitrilase accepts a wide range of substrates (Table 8). Even though many of them have low solubility in water, such as (88), the yields are in the range of 90%. Carboxylic esters are not susceptible to the hydrolysis by the enzyme so that only the cyano group of (89) is hydrolyzed. This mode of selectivity is opposite to that observed upon the chemical hydrolysis at alkaline pH, esters are more labile than nitriles. Dinitriles (90,91) can be hydrolyzed regioselectively resulting in cyanoacids in 71—91% yield. Hydrolysis of (92) proceeds via the formation of racemic amide which is then hydrolyzed to the acid in 95% ee (118). Prochiral 3-substituted glutaronitriles (93) are hydrolyzed by Phodococcus butanica in up to 71% yield with excellent selectivity (119). 

Plasticizers include the esters of a few aliphatic and aromatic mono and dicarboxylic acids, aliphatic and aromatic phosphorus acid esters, ethers, alcohols, ketones, amines, amides, and non-polar and chlorinated hydrocarbons. These additives are used in various mixtures. For their separation and qualitative detection, thin-layer chromatography (TLC) is preferred. Usually Kieselgur plates, 0.25 mm thick, activated at 110°C for 30 min, in the saturated vapor are used. Methylene chloride and mixtures of diisopropyl ether/petether at temperatures between 40 to 60°C have been successfully used as the mobile phase. Refer to Table 1. 

A broad spectrum of hydrogen-containing nucleophiles react with both aromatic and aliphatic isocyanates compounds containing OH groups (H20, alcohols, phenols, oximes, acids), SH groups (H2S, mercaptans), NH groups (NH3, amines, hydrazines, amides, ureas, urethanes), enolizable compounds such as malonic and aceto acetic esters, etc. Some reactions are given in Table 2.5. 

Enzymes are made from just 20 a-amino acid building blocks (structures and abbreviations are shown in Table 5.1). Each amino acid has a unique side chain, or residue, which can be polar, aliphatic, aromatic, acidic, or basic. The amide bonds (peptide bonds) make up the enzyme s backbone, and the residues determine the ultimate structure and catalytic activity of the enzyme. When the sequence of amino acids (the primary structure) for an enzyme is assembled in vivo, it folds... 

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