Amino acids diacid chloride reaction

The first, and still widely used, polymer-supported ester is formed from an amino acid and a chloromethylated copolymer of styrene-divinylbenzene. Originally it was cleaved by basic hydrolysis (2 N NaOH, FtOH, 25°, 1 h). Subsequently, it has been cleaved by hydrogenolysis (H2/Pd-C, DMF, 40°, 60 psi, 24 h, 71% yield), and by HF, which concurrently removes many amine protective groups. Monoesterification of a symmetrical dicarboxylic acid chloride can be effected by reaction with a hydroxymethyl copolymer of styrene-divinylbenzene to give an ester a mono salt of a diacid was converted into a dibenzyl polymer. ... 

It is also possible to prepare them from amino acids by the self-condensation reaction (3.12). The PAs (AABB) can be prepared from diamines and diacids by hydrolytic polymerization [see (3.12)]. The polyamides can also be prepared from other starting materials, such as esters, acid chlorides, isocyanates, silylated amines, and nitrils. The reactive acid chlorides are employed in the synthesis of wholly aromatic polyamides, such as poly(p-phenyleneterephthalamide) in (3.4). The molecular weight distribution (Mw/Mn) of these polymers follows the classical theory of molecular weight distribution and is nearly always in the region of 2. In some cases, such as PA-6,6, chain branching can take place and then the Mw/Mn ratio is higher. 

The common condensation polymers and the reactions by which they are formed are shown in Table 1-1. It should be noted from Table 1-1 that for many of the condensation polymers there are different combinations of reactants that can be employed for their synthesis. Thus polyamides can be synthesized by the reactions of diamines with diacids or diacyl chlorides and by the self-condensation of amino acids. Similarly, polyesters can be synthesized from diols by esterification with diacids or ester interchange with diesters. 

AminoFischer s base was condensed with the diacid chlorides of glutaric, pimelic, and azelaic acids to give in 70-92% yields the bis-amides, which upon reaction with 5-nitrosalicylaldehyde gave 70-88% of the bis-spiropyrans (72, n = 3,5,7). The alternative route, reaction of the acid chlorides with 5 -amino-6-nitroBIPS, is impractical because of the difficulty of obtaining this BIPS. The bis-BIPS exhibit strong photochromism. The open forms precipitate in nonpolar... 

There are five primary methods to polymerize nylon. They are reaction of a diamine with a dicarboxylic acid, condensation of the appropriate amino acid, ring opening of a lactam, reaction of a diamine with a diacid chloride, and reaction of a diisocyanate with a dicarboxyhc acid. ... 

The fact that polycondensations under the Yamazaki conditions employ free carboxylic acids instead of their chlorides, allows the use of either diacid or amino acid monomers separately or together in the same polymerization. This leads to a remarkable versatility in the creation of rigid networks out of aromatic polyamides. It further allows us to use in a Schotten-Baumann [403-408] type reaction in DM Ac mixtures of acid chlorides and free acids with aromatic amines to create certain aromatic branchpoints of particular size of functionality as shown below... 

The diester 23 was hydrolyzed to diacid 24, and then dehydrated to give anhydride 25. Subsequent reaction of this anhydride with amino amide 26 in acetonitrile gave two regioisomeric acid diamides 27 and 28 in the approximate ratio of 10 to 1. Pure 27 was isolated in 85% yield by heating the mixture in methylene chloride followed by extraction with 5% aqueous NaOH at room temperature. Treatment of 27 with 5% aqueous NaOH at 80 C then led to cyclization forming the desired imidazolinone 5. Its structure was confirmed by spectroscopic data and elemental analysis. 

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