Bis imidate

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). 

Because of the structural requirements of the bielectrophile, fully aromatized heterocycles are usually not readily available by this procedure. The dithiocarbamate (159) reacted with oxalyl chloride to give the substituted thiazolidine-4,5-dione (160) (see Chapter 4.19), and the same reagent reacted with iV-alkylbenzamidine (161) at 100-140 °C to give the 1 -alkyl-2-phenylimidazole-4,5-dione (162) (see Chapter 4.08). Iminochlorides of oxalic acid also react with iV,iV-disubstituted thioureas in this case the 2-dialkylaminothiazolidine-2,4-dione bis-imides are obtained. Thiobenzamide generally forms linear adducts, but 2-thiazolines will form under suitable conditions (70TL3781). Phenyliminooxalic acid dichloride, prepared from oxalic acid, phosphorus pentachloride and aniline in benzene, likewise yielded thiazolidine derivatives on reaction with thioureas (71KGS471). 

Addition of Azaenolates from 3,6-Dialkoxy-2,5-dihydropyrazines (Bis-Imidate Anions)... 

Power and coworkers prepared the iron(V) bis-imide complex 3,5-Pr2 Ar Fe[N (1-Ad)]2l [42]. This complex has been characterized by X-ray crystallography with the iron in planar three-coordinate geometry. The Fe-N bond distances are 1.642(2) and 1.619(2)A. Magnetic studies of 3,5-Pr2 Ar Fe[N(l-Ad)]2 reveals that this complex has a low-spin cP configuration with S = jl ground state. This compound is notable as it is a stable Fe(V) imide being well characterized. 

Imidazole sind der N-Oxidation mit Persauren im allgemeinen nicht zuganglich449. Der einzige Hinweis in der Literatur auf die Herstellung von 1 -Hydroxy-imidazolen oder Imidazol-3-oxiden durch Oxidation von Imidazolen ist die Herstellung von 1,1 -Dihydroxy-2,2 -bi-imid-... 

Das Erhitzen von 4,5-Dicarboxy-imidazolen mit Essigsaureanhydrid ist die Methode der Wahl zur selektiven Abspaltung einer Carboxy-Gruppe. Im Fall von 1-unsubstituierten Imidazolen erhalt man durch Kochen mit Essigsaureanhydrid 5,10-Dioxo-5H,10H-532 533 ... 

The monomer 91 was prepared in a multistep process and the authors did not quote the yield obtained for the final product (Fig. 41). In the first step the dianhydride 87, was reacted with m-nitroaniline 88 to form the mono imide anhydride 89 without any of the bis imide product being reported. Once this material was isolated the remaining anhydride functionality was reacted with 4-aminobenzocyclobutene 60 to form the JV-benzocyclobutenyl imide, 90. The nitro group was reduced to the amine (H2,10% Pd/C) which in turn was reacted with maleic anhydride to afford the final AB monomer, 91. Polymerization of 91 was carried out in a DSC (10 °C/min to 450 °C) [14]. Monomer 91 had a melting point of 99 °C and the final homopolymer had a Tg of257 °C [14]. A TGA of the homopolymer indicated that at 508 °C the polymer suffered a 10% weight loss. 

The reaction of the bulky amine ButNH2 with WCl in hexane affords the four-coordinate bis-imide as shown (equation 36).64... 

The reaction of chromenes with mono- and bis- imides of 1,4-benzoquinones (6, X = O or NCOPh) is promoted by Lewis acids and affords pterocarpans and azapterocarpans, respectively (95TL2713). A total synthesis of the pterocarpan, neorautenane, involves a chemoselective coupling of a benzodipyran with o-chloro-mercuriophenol (95JCS(P1)949). 

Reaction of oxalyl chloride with compound 301 gives the thiazolidine-4,5-dione 302 (Scheme 146), and the same reagent with A-alkylbenzamidine 303 at 100-140G affords the l-alkyl-2-phenylimidazole-4,5-dione 304 (Scheme 147). Imi-nochlorides of oxalic acid react with N,N-disubstituted thioureas to give the 2-dialkylaminothiazolidine-4,5-dione bis-imides 305. Phenyliminooxalic acid dichloride likewise yielded thiazolidine derivatives on reaction with thioureas <1971KGS471>. 

Nitrosamin (Ethylthio-methyl)-methyl- E14a/3, 522 (Imin + NOCl/R-SH) 1,4-Oxathian -4,4-bis-[imid] Ell, 1322 (1,4-Oxathian + NH3/ R-OC1)... 

Preparative Methods both enantiomers are readily prepared in one step from diethyl malonate or malono-bis-imidate and the corresponding amino alcohols. ... 

Diamino-1 H-pyrazole sind aus Malonsaure-dinitril und Hydrazinen direkt nicht er-haltlich. Zur Synthese geht man von Malonsaure-bis-[imid]-diestern aus, die durch Pinner-Reaktion aus Malonsaure-dinitril zuganglich sind438 439. 

Benzylideneanilines have been added across 2,3-dihydrofurans to produce bicyclic azetidines regio- and stereoselectively a zwitterionic mechanism is proposed. An extensive range of reaction parameters have been calculated for the Mannich reaction of benzoxazole with formaldehyde/dimethylamine. A molybdenum bis(imide) has been used to catalyse C=N bond formation in imine-imine metathesis reactions of synthetic interest the approach has been extended to alkylidene-imine, imide-imine, and imide-imide metatheses. 1-Substituted 1-phenyl-... 

The first step of this synthesis is to form a bis-imide monomer formed by the reaction of nitrophthalic anhydride and a diamine (see Figure 4.21). The second step of polyetherimide synthesis involves the formation of a bisphenol dianion by treatment of a diphenol with two equivalents of base, followed by... 

The significance of imidoyl halides as intermediates in the Beckmann rearrangement has been pointed out earlier (see Chapter 3). In the Chapmann rearrangement imidoyl chlorides are used to prepare imidates, which undergo rearrangement to yield N-aroyl derivatives of diarylamines C ). For example, reaction of the sodium salt of dimethyl 4,6-dihydroxyisophthalate (XIX) with the benzimidoyl chloride XX yields the bis-imidate XXI, which can be thermally rearranged and hydrolyzed to produce the diamines XXII C). 

Two types of thermoset polyimides are currently prepared commercially. They are based on low molecular weight bis imides such as bis maleimides or bis-5-norbomene-2,3-dicarboximides. Due to unsaturations, the materials cross-link by free-radical mechanism into tight networks. Michael type additions of primary and secondary amines to the bis maleimides are often used to chain-extend them before cross-linking. This reduces the cross-linking density and the brittleness [115]. The materials are designated by the term PMR, for polymerizable monomeric reactants. 

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