Diethyl oxaloacetate

The synthesis of this aminoquinoline starts with one of the standard sequences for preparation of 4-hydroxyquinolines, i.e., with the formation of the Shiff base (5) from the appropriately substituted aniline and diethyl oxaloacetate. Thermal cycliza-tion gives the quinolone (6) this then spontaneously tautomerizes to the enol form (7). Saponification followed by decarboxylation gives the desired quinolol... 

Dimethyl-3/7-indole reacts with diethyl oxaloacetate in acetic acid to give the pyrrolizine 157. Upon reaction of this product with guanidine for extended periods of time, the tetracyclic product 158 is formed in low yield <1988J(P1)451> (Scheme 46). 

Condensation of 3-amino-2-(methylamino)pyridine 647 with diethyl 2-oxomalonate in boiling ethanol afforded 2-carbethoxy-4-methylpyrido[2,3- ]pyrazin-3(4//)-one 213 <1996JHC1737>. On the other hand, condensation of 647 with diethyl oxaloacetate gave ethyl [2(l//)-oxopyrido[2,3- ]pyrazine-3(4//)-ylidene]carboxylate 648 in addition to the formation of pyridodiazepine 649 as a by-product <1996JHC1737>. However, the condensation of 647 with diethyl 2-oxoadipate gave the 2-ethoxycarbonylpropyl analogue 650 (Scheme 30) <1994FA259>. 

Diacetyltartaric anhydride, acetoxy maleic anhydride and diethyl oxaloacetate all yield carbon suboxide, C3O2 on pyrolysis. Carbon suboxide and protonated carbon suboxide are prominent ions in the mass spectra of all three of these compounds. 

Compound I features three carbonyl centers of various degrees of reactivity. It also displays a potentially acidic proton on the carbon between the /3-keto ester and lactone carbonyls. In principle, the carbanion derived therefrom should be comparable to the useful /3-keto ester anions in nucleophilic substitutions and additions that lead to the formation of C-C bonds. Diethyl oxaloacetate, however, is a very poor nucleophile, because epoxides and enones remain unaltered in its presence. This peculiarity poses severe restrictions to the synthetic applications of this reaction. 

The use of Al(Hg) in ether for the reduction of alkali-sensitive compounds may give higher yield than Na(Hg) thus, diethyl oxaloacetate is reduced to diethyl malate by Al(Hg) in 70-80% yield, whereas Na(Hg) gives about 50% yield [78]. 

The key intermediate for synthesizing chloroquine, amodiquine and other 4-aminoquinoline drugs is 4,7-dichloroquinolihe (91), which can be prepared by reacting m-chloroaniline (83) with diethyl oxaloacetate (EtO-CO-CH2-CO-COOEt) or ethoxy methylene malonic ester [EtO-CH=C(CCXDEt)2] as shown in scheme 1 [8,128-133]. 

After citation of ref. 4] Pelletier and Hawley 43 worked out a procedure for the large-scale preparation of 2-furoic acid involving the synthesis of furanetetracar-boxylic acid from Eastman s diethyl oxaloacetate and decarboxylation with Baker s copper powder and quinoline in a nitrogen atmosphere. 

In 1/7-2,4-Dihydropyrimido[4,5-[Pg.131]

The anhydride function of 1 7/-2,4-dihydropyrimido[4,5-r/][l,3]oxazine-2,4-diones 6 has been used to C-acylate the anion of diethyl oxaloacetate. In dimethylformamide at 110 °C cyclization with the amino group set free in the 6-position yields the pyrido[2,3-t/]pyrimidin-5(8/7)-one 7.289... 

A convenient synthesis of pyridazine-3,4-dicarboxylic acid based on [4 + 2] cycloaddition of an electron deficient diazadiene has been developed (Scheme 102) and carried out on a molar scale. The azadiene is generated in situ from the precursor (124) (prepared from diethyl oxaloacetate and methyl carbazate followed by chlorination with sulfuryl chloride) and trapped with ethyl vinyl ether. The regiospecific cycloaddition gives the tetrahydropyridazine (125) as a mixture of cis and trans isomers which, with bromine in acetic acid, are transformed into diethyl pyridazine-3,4-dicar-boxylate. Saponification gives the diacid in an overall yield of 52% <90JHC579>. In a similar approach from the readily available ethyl 2-chloro-3-oxobutanoate, an efficient route to ethyl 3-methylpyridazine-4-carboxylate has been developed which gives the product in 56% overall yield. This route is claimed to be a practical alternative to the radical ethoxycarbonylation of pyridazines <91JHC1043>. 

AI3-04820 Butanedioic acid, oxo-, diethyl ester, ion(l-), sodium Diethyl oxalacetate sodium salt Diethyl oxaloacetate, monosodium salt Diethyl oxobutanedloate ion(l-) sodium Diethyl sodiooxalacetate Diethyl sodium oxalacetate EINECS 255-122-9 NSC 126906 Oxalacetic acid diethyl ester sodium salt Sodium diethyl oxaloacetate Sodium diethyl oxobutanedloate. 

Ethyl picolinate failed to undergo condensation with diethyl oxaloacetate (XI-46) (using Claisen conditions) to give the desired product XI-47. ... 

Diethyl oxaloacetate, condensation with ethyl picollnate, 343... 

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