Amines with carboxylic acid anhydrides

Carboxylic acids were introduced by the reaction of the polysilane(II) with carboxylic acid anhydrides in the presence of an amine. Table 2 shows the results. In order to examine the effect of unsaturated bonds and halides in the side chain on photolysis, double bonds or chloride groups were introduced with the carboxylic acid. Polysilanes(III) were also soluble in polar solvents and basic aqueous solution. The solubility in tetramethyl ammonium hydroxide aqueous solution(TMAH) depended strongly... 

Crosslinking of epoxy resins with carboxylic acid anhydrides is catalyzed by tertiary amines thus,if 50 mg /V,/V-dimethyl aniline are added to the initial mixture in the above example, the curing process is already complete after 1 h at 120 °C. 

The T2 linker has recently been shown to be a versatile backbone amide anchor. Immobilized disubstituted triazenes were acylated with carboxylic acid anhydrides or chlorides to give amide derivatives. These amides were cleaved under very mild conditions using trimethyl chlorosilane. This sequence thus employs the T2 system as backbone amine linker and was demonstrated in the automated library synthesis of substituted amide derivatives.54... 

Poly(dimethyl siloxane) (PDMS) stamps with protruding features (e.g., 1-pm lines or 10 pm squares on a side) may be inked with hexadecyl amines and pressed on smooth substrates covered with carboxylic acid anhydride surfaces. These in turn are obtainable by SAMs of fatty acids and subsequent dehydration. Hexadecylamide patterns are thus formed on carboxylate surfaces. Unreacted sites still contain anhydrides for further self-assembly processes to fill the voids ( micrometer or nanometer printing thiols or Kumar et al., 1995). 

With regard to reactively compatibilized TPU blends, Lu et al. (2002) determined the relative reactivity of various functionalities toward TPU using model compounds. The ranking of relative reactivity was found to be primary amine (most reactive) > seccmdaiy amine >> hydroxyl carboxylic acid anhydride >> epoxide (least reactive). 

Amides are common structures and they are important and versatile synthons to prepare pharmaceuticals, agrochemicals, materials and some specialty chemicals. Many methods have been developed to synthesize primary amides, secondary amides as well as tertiary amides. The traditional process to construct amide bond is the acylation of amines with carboxylic acid or carboxylic acid daivatives such as acid chlorides as well as anhydrides [1, 2]. Furthermore, the Schmidt reaction [3] and Beckmann rearrangement [4] also have been well developed for the amide synthesis. Recently, some reviews have been well summarized the synthesis routes of these amides [5-17]. In this chapter, we will focus on the recent progresses about amide synthesis only by N, NH, or NH2 atoms incorporation nitrogenation strategy via C-H and/or C-C bond cleavage. A series of nitrogen sources such as sodium... 

Amines are convert ed to amides on reaction with acyl chlorides Other acylating agents such as carboxylic acid anhydrides and esters may also be used but are less reactive... 

The classes of compounds which are conveniently considered together as derivatives of carboxylic acids include the carboxylic acid anhydrides, acyl chlorides, esters, and amides. In the case of simple aliphatic and aromatic acids, synthetic transformations among these derivatives are usually a straightforward matter involving such fundamental reactions as ester saponification, formation of acyl chlorides, and the reactions of amines with acid anhydrides or acyl chlorides ... 

In Chapter 2 the DSC technique is discussed in terms of instruments, experimental methods, and ways of analysing the kinetic data. Chapter 3 provides a brief summary of epoxy resin curing reactions. Results of studies on the application of DSC to the cure of epoxy resins are reviewed and discussed in Chapter 4. These results are concerned with the use of carboxylic acid anhydrides, primary and secondary amines, dicyanodiamide, and imidazoles as curing agents. 

Sulfonamides prepared from 9-(chlorosulfonyl)anthracene and polystyrene-bound primary amines can be converted into amides by N-acylation of the sulfonamide (carboxylic acid anhydride, DMAP, pyridine, THF, 24 h) followed by nucleophilic desulfo-nylation with neat 1,3-propanedithiol/DIPEA [213] (Entry 4, Table 10.13). An example of the use of sulfonamides as linkers for amines is given in Table 3.23. 

Triaminophosphonium salts, unlike carbodiimides, only react with carboxylic acids under basic conditions, thereby yielding acyloxyphosphonium salts (Figure 13.5). Depending on the counterion X and on the precise reaction conditions, the acyloxyphosphonium salt can either acylate the amine directly or be transformed into the symmetric anhydride or an active ester [2,82], which then acylates the amine. At low... 

Fluorinated alkylisocyanates and isothiocyanates add alcohols, mercaptans, and amines to yield stable 1 1 adducts [76]. When the reaction is performed with carboxylic acids, the anhydrides first formed decompose to give A -fluoroalky-lated amides [77]... 

Carboxylic acids react with aryl isocyanates, at elevated temperatures to yield anhydrides. The anhydrides subsequently evolve carbon dioxide to yield amines at elevated temperatures (70—72). The aromatic amines are further converted into amides by reaction with excess anhydride. Ortho diacids, such as phthalic acid [88-99-3], react with aryl isocyanates to yield the corresponding N-aryl phthalimides (73). Reactions with carboxylic acids are irreversible and commercially used to prepare polyamides and polyimides, two classes of high performance polymers for high temperature applications where chemical resistance is important. Base catalysis is recommended to reduce the formation of substituted urea by-products (74). 

The polymerisation of a-aminoacid A-carboxyanhydride, which is accompanied with the elimination of carbon dioxide, constitutes a convenient method for preparing high molecular weight polypeptide. This polymerisation, with the use of a-aminopropionic acid (alanine) A-carboxylic acid anhydride as a monomer, was also carried out in the presence of coordination catalysts such as group 2 and 3 metal alkyls [168-174] or their combinations with water, secondary amine or alcohol [168,173] and yielded polyalanine (Table 9.2). 

In the Friedel-Crafts acylation, carboxylic acid chlorides and carboxylic acid anhydrides are activated with stoichiometric amounts of A1C13 (Section 5.2.7). However, this activation is only possible in the presence of very weak nucleophiles such as aromatic compounds. Stronger nucleophiles would react with the A1C13 instead of the carboxylic acid derivative. If one wants to acylate such stronger nucleophiles—for example, alcohols or amines—with car-... 

The last of these special examples of SN reactions of heteroatom nucleophiles at the carboxyl carbon of a carboxylic acid derivative is given in Figure 6.21. There, the free carboxyl group of the aspartic acid derivative A is activated according to the in situ procedure of Figure 6.14 as a mixed carbonic acid/carboxylic acid anhydride B that is then treated with N,0-dimethylhydroxyl amine. This reagent is an N nucleophile, which is thus acylated to give the... 

Under suitable conditions, amide formation can take place between an amine and a carboxylic acid, an acyl halide, or an acid anhydride. Along with ammonia, primary and secondary amines yield amides with carboxylic acids or derivatives. Table 33.2 relates the nitrogen base with the amide class (based on the number of alkyl or aryl groups on the nitrogen of the amide). 

Amino acids exhibit chemical reactions that are typical of both amines and carboxylic acids. For example, the acid can be converted to an ester by the Fischer method. This reaction requires the use of an excess of acid because one equivalent is needed to react with the amino group of the product. As another example, the amine can be converted to an amide by reaction with acetic anhydride. Additional examples are provided by the reactions that are used in the preparation of peptides from amino acids described in Section 26.7 ... 

Cleavage of an ester by ammonia (or an amine) to give an amide and an alcohol, (p. 1003) (carboxylic acid anhydride) An activated acid derivative formed from two acid molecules with loss of a molecule of water. A mixed anhydride is an anhydride derived from two different acid molecules, (p. 986)... 

Using the principles we ve outlined above, you should be able to see how these compounds can be interconverted by substitution reactions with appropriate nucleophiles. We ve seen that acid chlorides react with carboxylic acids to give acid anhydrides, and with alcohols to give esters. They ll also react with amines (such as ammonia) to give amides. 

Photocationic initiators. Epoxy resins can be cross-linked by compounds containing active hydrogen, e.g., carboxylic acids, anhydrides, amines, phenols etc., or by the ionic polymerization process. Lewis acids such as BF3 and usually a crystalline complex of BF3 with amines, e.g., BF3 NH2C2H5, can be used for curing reaction at 80-100° C [124]. 

Reaction with Carboxylic and Inorganic Acids. The reaction of carbodiimides with carboxylic acids has dual character because acyl ureas 484 or acid anhydrides 485 are formed. Often mixtures of both products are formed. The product formation depends on the nature of the reagents and the reaction conditions. With aromatic carboxyhc acids mainly N-acylureas are formed, and in the presence of tertiary amines the anhydride formation is inhibited." ... 

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