Dicarboxylic acid amides cyclic

Cooper and Cronin (1995) detected a wide range of linear and cyclic amides in water extracts of Murchison, extending the previous positive detection of guanylurea (Hayatsu et al., 1968) These included many mono- and dicarboxylic acid amides, hydroxyacid amides, and other amides with no known terrestrial source. These compounds were characterized by a stmctural diversity of isomers up to Cg and a decline in abundance with increasing carbon number. 

Cyclic amines from dicarboxylic acid amide esters... 

Cyclic mew-configurated 1,2-dicarboxylic acid dimethyl esters are excellent substrates for pig liver esterase90. Cyclopropanedicarboxylales have been studied not only for synthetic reasons, but also so that an active-site and/or substrate model of pig liver may be developed13 5. The results obtained, compounds 11-17, are a good demonstration of the scope and limitation of PLE in asymmetric synthesis. Enantiomeric excesses of the monoesters can be determined by conversion into the amides with (S)-l-phenylethylamine and analysis either by GC or H-NMR spectroscopy, whereas the absolute configuration rests on chemical correlation. 

In the last few years, Hamilton has published reports of a series of open chain or cyclic receptors featuring 2-acylaminopyridine units as combined H-bond donor and acceptor groups [30]. The simple terephthaloyl derivative 22 forms stable complexes with dicarboxylic acids of appropriate chain length, like adipic and glutaric acid, in CDCI3 [31]. Additionally, complexation influences the s-cis s-trans ratio of the amide bond in acylprolines [32]. 

S.K. Callear, M.B. Hursthouse, T.L. ThrelfaU, Cocrystallization of organic a,co-dicarboxylic acids with the cyclic amides 2-pyrrolidmone and 2-imidazolidinone, CrystEngComm 11 (2009) 1609-1614. 

Sn[N(TMS)2l2, A, A -carbonyldiimidazole (110, p. 1418), which behaves as in reaction 16-63, POCl3, °" TiCl4, ° molecular sieves,Lawesson s reagent (p. 1278), ° and (MeO)2POCl. ° Certain dicarboxylic acids form amides simply on treatment with primary aromatic amines. In these cases, the cyclic anhydride is an intermediate and is the species actually attacked by the amine. Carboxylic acids can also be converted to amides by heating with amides of carboxylic acids (exchange),sulfonic acids, or phosphoric acids, for example, ... 

In an extension of earlier work, Buigada et al. have also reported on the reaction of the cyclic phosphite (66) with dimethylacetylene dicarboxylate (58) in the presence of proton sources such as carboxylic acids, amide N-H bonds in succinimide or phthalimide and amine N-H bonds in p UTole or indole. With carboxylic acids (67) a mixture of the ylid (68) and the cyclic phosphorane (69) was obtained and in some instances (e.g. with 2,4,6- trimethylbenzoic and p-methoxybenzoic acids) the ylid and phosphorane were shown to be in equilibrium. With amides as the proton source, ylids were generally formed although with N-methylbenzamide (PhCONHMe)a signal attributed to (70) was observed at = - 52 p.p.m. which had disappeared by the end of the reaction through rearrangement to (71). With amines (e.g. pyrrole) the products were again a mixture of ylid (72) and phosphorane (73) and the entire set of results was rationalised in terms of HSAB theory and the symbiotic effect around phosphorus. 

The above mentioned methods for preparation of cyclic bis-amides were patterned after peptide chemistry reactions where amide bonds dominate. Also in peptide chemistry, DCC, and DCC plus 1-hydroxybenzotriazole (HOBT) have been used in amide formation reactions. Using this procedure, 16-membered peraza-crowns have been prepared in 50-55% yields for the cyclization step (Vellacio et al., 1977). The carboxyl group can also condense with secondary amines in DMF in the presence of 1.1 mol of DCC and 1.2 mol of HOBT per mole of the dicarboxylic acid (Krakowiak et al., 1989). 

Diphenylphosphoryl azide (DPPA) has also been used as an activating agent for the ring closure of dicarboxylic acids with polyamines to give high yields of the cyclic bis-amides (Qian et al., 1990). Cryptands have also been... 

The orange-red actinomycins 37 (Waksman 1940) found in various types of streptomyces are 2-aminophenoxazone-l,9-dicarboxylic acids which are linked as amides to cyclic pentapeptide units. They are able to intercalate into DNA and are employed as cytostatic agents in tumour therapy. 

Metallocenes 21-23 were found to bind mono- and dicarboxylic acids in organic solvents through complementary hydrogen bonds with their amide (N—H... O) and pyridine (O-H...N) groups. Cyclic voltammetry studies in CH2CI2 revealed cathodic shifts in the Fc /Fc redox couples, with the redox response to complexation of the monoacid decanoic acid by 21 and 22 ( — 25 mV and... 

Thermal degradation of various aliphatic polyamides was also studied by Py-EIMS, Py-field ionization (FI), and field desorption (FD)-MS. The Py-EIMS studies demonstrated that the polylactams mainly decomposed to cyclic oligomers, whereas the favored decomposition pathways of diamine-dicarboxylic acid-type polyamides were the cis elimination reaction and the cleavage of the amide bond, which also occurred in the polylactams with a large number of methylene groups, such as nylon 12. On the other hand, Py-FIMS of various diamine-dicar-... 

Polyamides contain the amide group —NH—CO— and can be classified in two homologous series. In the Perlon series, monomeric and repeat units are identical, since these polyamides occur either by the polymerization of lactams (cyclic amides) or the polycondensation of co-amino carboxylic acids. In contrast, the polyamides in the Nylon series are formed by the poly condensation of diamines and dicarboxylic acids Thus, two monomeric units form one repeat unit. 

General methods for the synthesis of poly(amide-anhydrides) and poly(amide-esters) based on naturally occurring amino acids were described (Domb et at, 1990). The polymers were synthesized from dicarboxylic acids prepared by amidation of the amino group of an amino acid with a cyclic anhydride, or by the amide coupling of two amino acids with a diacid chloride. Low molecular weight polymers from methylene bis(p-carboxybenzamide) were symthesized by melt condensation (Hartmann et al, 1989). A series of amido containing polyanhydrides based on p-aminobenzoic acid were sy nthesized by melt condensation. The polymers melted at 58 to 177°C and had a molecular weight of 2500 to 12400. 

There are cyclic esters (known as lactones), cyclic amides (known as lactams), cyclic anhydrides, and cyclic imides. The structures for these derivatives are presented in Chapter 20, Section 20.6.5. The chemical reactions associated with derivatives of dicarboxylic acids are discussed in Chapter 20 as well. 

This chapter will discuss methods for the preparation of esters, acid chlorides, anhydrides, and amides from carboxylic acids, based on acyl substitution reactions. Acyl substitution reactions of carboxylic acid derivatives will include hydrolysis, interconversion of one acid derivative into another, and reactions with strong nucleophiles such as organometallic reagents. In addition, the chemistry of dicarboxylic acid derivatives will be discussed, as well as cyclic esters, amides, and anhydrides. Sulfonic acid derivatives will be introduced as well as sulfate esters and phosphate esters. Finally, nitriles will be shown to be acid derivatives by virtue of their reactivity. 

Imides are formed by the reaction of amides with other acid derivatives. Cyclic anhydrides and cyclic imides can be prepared from dicarboxylic acids or acid dichlorides. 

The formation of 20 is basically a reaction in which a 1,2-dicarboxylic acid and a 1,2-diamine react to form a cyclic diamide or hydrazide. The mechanistic steps by which an acid and amine are converted to an amide are portrayed in Scheme 20.4. The acid and amine are in rapid equilibrium with the corresponding ammonium salt and the carboxylate ion, the latter of which is not subject to nucleophilic attack at the carbonyl carbon atom. The acid itself may undergo nucleophilic attack, however, so the small amount of it that exists at equilibrium (see Exercise 4) reacts with free amine to produce the tetrahedral zwitterionic intermediate 21. Subsequent proton transfers and loss of water afford the amide 22. Repetition of this series of steps generates 20. 

The second largest volume nylon is nylon 6. Nylon 6 is not made from a diamine and a dicarboxylic acid, but from a six carbon cyclic amide. Cyclic amides are called lactams and caprolactam is a six-carbon lactam. Caprolactam can be made by the reaction of cyclohexanone with hydroxylamine, followed by a Beckmann rearrangement. 

Optically active stereoregular polyamides with restricted rotation around the amide bond derived from polycondensation of trans cyclic dicarboxylic acids (XXa-e) and of various diamines piperidine (PID), piperazine (PIP), trans-2,5-dimethylpiperazine(DMPIP), 7V,A -dimethylethylene diamine (DMED) and more recently 2,6-diazaspiro-3,3-heptane (DSH) [50]. 

Known examples of slip agents useful in photographic materials include polyor-ganosiloxanes, higher aliphatic amides, higher aliphatic esters, metallic salts of higher aliphatic acid, and polyester compounds made of dicarboxylic acid having up to 10 carbon atoms and aliphatic or cyclic aliphatic diol. ... 

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