Oxalacetic acid, 2- -, ethyl ester

This acetylpyridone diester 15 was conveniently synthesized in 60% yield by reacting acetoacetamide with ethoxy-methylene oxalacetic acid diethyl ester 14 in ethanol in the presence of sodium acetate (13). Compound 14 was prepared according to the procedure of R. G. Jones by condensing ethyl oxalacetate with ethyl orthoformate in the presence of acetic anhydride (14). It was found that purified compound 14 gave the best yield (60%) of acetylpyridone diester 15, but as a matter of convenience, crude 14 gave product 15 in up to 40% yield. Isolation of 15 was expedited by the precipitation of its sodium salt from the reaction mixture. 

Oxal-ither, oxalic ether (ethyl oxalate), -essigester, m. oxalacetic ester, -essigsaure, /, oxalacetic acid, -ester, m, oxalic ester (specif, ethyt oxalate),... 

Ethyl dnnamate occurs in small amounts in storax.1 It has been prepared by the action of ethyl alcohol on cinnamic acid in the presence of dry hydrochloric or sulfuric acid 2 by the distillation of the copper salt of the monoethyl ester of benzylidene oxalacetic acid 3 and by the condensation of ethyl acetate and benzaldehyde in the presence of sodium.4 The method described in the procedure is a slight modification of the one originally described by Claisen.5... 

These syntlieses give no indication as to the structure of aspartic acid, the constitutional formula of which is based upon Kolbe s work, that it is amino-succinic acid the only synthesis of aspartic acid which confirms this constitution appears to be that by Piutti in 1887. Sodium oxalacetic ester, prepared from oxalic ester and acetic ester in the presence of sodium ethylate —... 

A soln. of 4-amino-3-hydroxy-5-methylacetophenone and the equivalent amount of diethyl oxalacetate refluxed 1 hr. ethyl 5-methyl-7-acetylbenz-l,4-oxazin-2-on-3-ylacetate. Y ca. 90%.—Because these benz-l,4-oxazin-2-ones crystallize well and can be cleaved by alkali, they are suitable for the separation of aminophenols and the identification of the o-isomers. Even isomeric o-aminophenols can be separated due to different reaction rates. F. e. s. A. Butenandt, E. Biekert, et al., B. 92, 2172 (1959). Condensed l,4-oxazin-2-ones may also be used for the identification of a-ketocarboxylic acid esters. E. s. B.94, 1664 (1961). 

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