Tricarboxylic esters, preparation

Diaminobiuret has been prepared only from N-tricarboxylic ester and hydrazine hydrate.1 Ethyl hydrazinecarboxylate has been prepared by reduction of nitrourethan electrolytically2 or with zinc dust and acetic acid,3 and by the action of hydrazine hydrate on diethyl carbonate,4 6 ethyl chlorocarbonate,6 and N-tricarboxylic ester.1... 

Heterofunctionalized derivatives can be prepared following the same methodology. In the case of esters and halides, rhodium(II) acetate dimer must be employed as catalyst instead of copper compounds.After transformation of the acetoxymethyl group of 7 (X = OAc) into an ester functionality, these compounds are valuable precursors of highly functionalized bi-cyclo[1.1.0]butanes since nucleophilic attack on the keto group takes place under very mild conditions. Thus, the t> /o-bicyclo[1.1.0]butane-l,2,3-tricarboxylic ester is obtained from 3-oxo-tricyclo[2.1.0.0 - ]pentane-l, 5-dicarboxylic esters upon treatment with methanol at 20 °C for three hours. 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

PREPARATION AND INVERSE ELECTRON DEMAND DIELS-ALDER REACTION OF AN ELECTRON-DEFICIENT HETEROCYCLIC AZAOIENE TRIETHYL 1.2,4-TRIAZINE-3,5,6-TRICARBOXYLATE (l,2,4-Triazine-3,5,6-tricarbo orl 1c acid, triethyl ester)... 

The properties of he tetrabasic acid prepared from dibroiusuccinic ester by Perkin differed from the acids obtained in other ways. Buchner repeated this work,however,and got only the Known acid. (Cf.note on page 5. ) The 1,1,2,3 acid is also obtained by the action of barium hydroxide on dicyancyclopropane 1,2,3 tricarboxylate. ... 

The heteroaryllead tricarboxylates furyllead triacetate and thienyUead triacetate are much less stable than the benzenoid analogs and very sensitive to moisture. They were therefore prepared in situ and reaction with -carbonyls yielded the a-furyl and thienyl )5-keto esters in synthetically useful yields (Scheme 13.9) [37]. 

The title compound can be prepared by condensing an alkyl a-bromocaprylate with a trialkyl propane-1,1,3-tricarboxylate to give a substituted cyclopentanone. Hydrolysis, decarboxylation, and esterification of the resulting monocarboxylic acid with methanol yields the desired ester [139]. Trialkyl propane-1,1,3-tricarbox-ylates can be prepared by Michael addition of dialkyl malonates to alkyl acrylates. 

Chloroformyl(naphthalic anhydride), a derivative of naphthalene-1,4,5-tricarboxylic acid, and the acid itself were involved in preparing bis(naphthalic anhydrides) containing ester and amide groups (Scheme 26) ... 

Carbon-carbon bond formation by the addition of soft nucleophiles such as malonate enolates to 7r-allyl metal complexes continues to be a productive area. Various neutral tt-ally 1-iron complexes can be used to prepare esters (85) in this way while the tetracarbonyliron complex of methyl a-chloroacrylate undergoes a double addition to give polyester (86). Trost s group has shown that TT-ally 1-palladium complexes react completely stereoselectively as, for example, in the conversion of butyrolactone (87) into the tricarboxylate (88). ... 

The Knorr pyrrole synthesis was also employed for the synthesis of 3-trifluoropyrroles [91]. Treatment of ethyl trifluoroacetoacetate 267 with sodium nitrite in acetic acid led to the oxime 268. Refluxing with zinc dust and addition of 1,3-dicarbonyl compounds 269 afforded the 3-trifluoromethylpyrroles 270 in moderate yields. Using more acidic trifluoroacetic acid allowed to lower the reaction temperature to 70 °C [92]. Using a similar approach, the tricarboxylic acid ester 273 was prepared starting from the acetone dicarboxylic acid ester 271 and the fluorinated keto ester 272 [93]. 

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