Carboxylic imides

The carboxylic bisimide 1 is partially hydrolyzed [18] to form the anhydride carboxylic imide 2 according to Scheme 1. The bichromophore 4 is directly formed from 2 and stochiometric amounts of hydrazine, whereas an excess of hydrazine allows the preparation of the amino derivative 3. A condensation of 2 with 3 is an alternative to prepare 4. The trichromophore 6 is obtained from 3 and the bisanhydride 5. 

Intramolecular cyclization of 2-aminoethanesulfonyl halides gives 1,2-thiazetidine 1,1-dioxides ((3 sultams), as exemplified in the synthesis of 429. ° Treatment of 2-halosulfonylethanoyl halides with ammonia or primary amines yields 1,2-thiazetidin-3-one 1,1-dioxides, which are mixed sulfonic-carboxylic imides 430. A 3-imino derivative has also been obtained. ... 

Bromo-methyl-7-methoxycoumarin Br-Mmc Carboxyl, imide, phenol, thiol... 

Kimura and coworkers established that Zn + complexes of macrocyclic polyamines such as Zn -cyclen 1 (ZnL ) + are stable in aqueous solutions at neutral pH (Scheme 3.2) and are good models for Zn + enzymes such as carbonic anhydrase, alkaline phosphatase, class II aldolases, and related enzymes (cyclen = 1,4,7,10-tet-raazacyclododecane)." These Zn + complexes form 1 1 complexes (1-X complexes) with various anions, including carboxylates, imides such as thymine, phosphates, and thiolates. - ... 

The neutral and acid-catalyzed hydrolyses of a series of phosphoric carboxylic imides X2P(0)NRC(0)R (28) (X = EtO, MeO, Et R = H, Me R = Me, Ph) have been compared with the behavior of related carboxylic acid and phosphoric amides, particularly in acidic conditions where the latter two systems differ greatly. In acid the carboxylic amides react slowly by attack of solvent on the oxygen-protonated form of the substrate and the phosphoric amide reacts rapidly by direct Sjv2(P) displacement via an N-protonated substrate. The acid hydrolysis of (28) lies between these two extremes with the protonation of carbonyl oxygen stabilizing the resonance structure which renders the phosphorus atom more electrophilic and the P-N bond less labile with the consequence that the reactivity of the P-N and C-N linkages become comparable. ... 

Poly(n,n1,4-pheny lene-3,3 4,4 -benzophenone tetra-carboxylic imid/amic acid Benzophenonetetraoarboxylio dianhydride-/ -phenylenedianiine polymer, SRU 26023-2 1-2 Poly( 1,3-dihydro-1,3-dioxo-2H-isoindole-2 5-diyl)carbonyl- (1,3-dihydro-1,3-dioxo-2H- isoindole-5,2-diyl)- 1,4-phenylene) U (C23H loNiO ),... 

Amidation. A number of other various amidation reactions have been conducted using BOP. Such preparations include A) O-dimethyl hydroxamates of amino acids and peptides (precursors of chiral peptidyl aldehydes), heterocyclic amide fragments in the synthesis of macrolide and porphyrin models, dan-sylglycine anhydride as a mixed sulfonic-carboxylic imide by dehydration-cyclization of dansylglycine, and selective monoacylation of heterocyclic diamine in carbohydrate series (eq 9). ... 

Dilute sodium hydroxide solution. Carboxylic acids (RCOOH), sulphonic acids (RSO3H), phenols (ArOH), thiophenols (ArSH), mer-captans (RSH), imides (RCONHCOR), aryl sulphonamides (AxSOjNHj), arylsulphonyl derivatives of primary amines (AxSOjNHR), oximes (RCH=NOH), primary and secondary nitro compounds (RCH=NOOH and RjC=NOOH-oci forms), and some enols (e.g., of 1 3-diketones... 

Heating Kemp s acid with appropriate aromatic diamines yields bis-imides with two convergently oriented carboxylic acid groups on the edges of a hydrophobic pocket. Dozens of interesting molecular complexes have been obtained from such compounds and can be traced in the Journal of the American Chemical Society under the authorship of J. Rebek, Jr., (1985 and later e.g. T. Tjivikua, 1990 B). 

Hydrogenolysis of the diallyl alkylmalonate 757 with formic acid in boiling dioxane affords the monocarboxylic acid 758. Allyl ethyl malonates are converted into ethyl carboxylates[471]. The malonic allyl ester TV-allylimide 759 undergoes smooth deallylation in refluxing dioxane to give the simple imide 760(472]. The allyl cyanoacetate 761 undergoes smooth decarboxylation to give... 

Icosanoids (Section 26 6) A group of naturally occurring com pounds derived from unsaturated C20 carboxylic acids Imide (Section 20 16) Compound of the type... 

AijAT-dicyclohexylcarhodiimide (DCC) also leads to essentially quantitative conversion of amic acids to isoimides, rather than imides (30,31). Combinations of trifluoroacetic anhydride—triethjlarnine and ethyl chi oroform a te—triethyl amine also result in high yields of isoimides (30). A kinetic study on model compounds has revealed that isoimides and imides are formed via a mixed anhydride intermediate (12) that is formed by the acylation of the carboxylic group of amic acid (8). 

A variety of nucleophiles can be employed—e.g. carboxylic acids, phenols, imides, thiols, thioamides, and even /3-ketoesters as carbon nucleophiles. Of major importance however is the esterification as outlined above, and its use for the clean inversion of configuration of a chiral alcohol. 

Peptide synthesis requires the use of selective protecting groups. An N-protected amino acid with a free carboxyl group is coupled to an O-protected amino acid with a free amino group in the presence of dicydohexvlcarbodi-imide (DCC). Amide formation occurs, the protecting groups are removed, and the sequence is repeated. Amines are usually protected as their teit-butoxy-carbonyl (Boc) derivatives, and acids are protected as esters. This synthetic sequence is often carried out by the Merrifield solid-phase method, in which the peptide is esterified to an insoluble polymeric support. 

A similar irradiation of imide 9 in acetonitrile gives a mixture of ethyl 4,5-bis(ethoxy-carbonylamino)-l//-l,2-diazepine-l-carboxylate (10) and the isomeric ethyl 5,6-bis(ethoxycar-bonylamino)-l/f-l,2-diazepine-l-carboxylate (11) in the ratio 6 1. In contrast, when the irradiation is carried out in dichloromethane, the ratio is reversed to 1 2.5.81... 

For less hindered carboxylic acids acylation of the imidate requires only 5 minutes. With this modification the /V-(a-methoxybenzyl)amides are prepared according to the above-mentioned procedure [R = CH3, CH(CH,)2. CH(CH, )OAc, CH(C H2)OAc yield 85-88%]. 

Rhenium(VI) complexes, 4,194 alkoxides, 4,196 amides, 4,194 amines, 4,199 carboxylates, 4,199 dimethylformamide, 4,199 dioxane, 4,198 halides, 4,195,199 2-hydroxypyridine, 4,199 imides, 4,194 magnetic behavior, 1,271 mixed sulfur-nitrogen compounds, 4,196 N heterocycles, 4,199 nitrides, 4,194 oxide halides, 4, 195 oxoanions,4,196 pyridine, 4,199 sulfates, 4,198 sulfur compounds, 4,196 tellurates, 4,198... 

Fourier transform infrared (FTIR) spectroscopy is the most popular method for determining the imidization process in the solid state and identifying specific substituents on the macromolecular backbone (e.g., CN, SO3H, CO, SO2).131 A method for calculating the diermal imidization extent based on FTIR data has been reported by Pride.132 Raman spectroscopy was used on the model study of PMDA-ODA condensation, and the possible formation of an inline bond by reaction of an amino group with an imide carboxyle was evidenced.133... 

C for 6 h afforded the alkylated imides in 60-84% yields. The last approach was extended to unsaturated carboxylic amides. The diene 0,N-acetal 86 was prepared from the amide 85 in high yields and subsequently treated with azoinitiator V-70 to afford the desired products (Scheme 13). ... 

As in 10-55 hydrazides and hydroxamic acids can be prepared from carboxylic esters, with hydrazine and hydroxylamine, respectively. Both hydrazine and hydroxylamine react more rapidly than ammonia or primary amines (the alpha effect, p. 445). Imidates, RC(=NH)OR, give amidines, RC(=NH)NH2. Lactones, when treated with ammonia or primary amines, give lactams. Lactams are also produced from y- and 5-amino esters in an internal example of this reaction. 

Imides can be prepared by the attack of amides or their salts on acyl halides, anhydrides, and carboxylic acids or esters. The best synthetic method for the preparation of acyclic imides is the reaction between an amide and an anhydride at 100°C catalyzed by H2S04. When acyl chlorides are treated with amides in a2 l molar ratio at low temperatures in the presence of pyridine, the products are N,N-diacylamides, (RCO)3N. ... 

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