Diethyl aminomalonate

Diethyl acetamidomalonate was first reported by Cherchez in 1931, when in an attempt to carry out a carbon alkylation of diethyl aminomalonate with acetyl chloride he obtained a quantitative yield of diethyl acetamidomalonate. This method of preparation, however, is not practical since diethyl aminomalonate is unstable and is made in relatively poor yields. 

Snyder and Smith prepared diethyl acetamidomalonate in 40% yield by reduction of diethyl isonitrosomalonate in ethanol over palladium on charcoal followed by direct acetylation of diethyl aminomalonate in the filtrate with acetic anhydride. Ghosh and Dutta used zinc dust instead of palladium. A modification using Raney nickel is described by Akabori et al. Shaw and Nolan reported a 98% yield by conversion of diethyl oximino-malonate-sodium acetate complex. 

DIETHYL AMINOMALONATE HYDROCHLORIDE (Malonic acid, amino-, diethyl ester, hydrochloride)... 

B. Diethyl aminomalonate hydrochloride. The crude diethyl aminomalonate is diluted with 80 ml. of dry ether and filtered to remove a small amount of white solid. The filtrate is collected in a 250-ml. Erlenmeyer flask and cooled in an ice bath. Dry hydrogen chloride is passed just over the solution while it is being stirred mechanically (Note 6). The fine white crystals which precipitate are collected by suction filtration and washed three times with a total of 60 ml. of dry ether (Note 7). The filtrate and washings are treated again with hydrogen chloride, and a second crop of diethyl aminomalonate hydrochloride is collected and washed as before. This process is repeated until no further precipitation results from passing hydrogen chloride into the solution. A total of 16.5-17.4 g. (78-82% yield based on diethyl malonate) of diethyl aminomalonate hydrochloride, m.p. 162-163°, is obtained. Recrystallization from alcohol-ether affords a purer product, 164-165°. 

Diethyl aminomalonate is a useful intermediate, lending itself to N-acylation the N-acyl derivatives may be alkylated by procedures as established for syntheses via malonic ester. 

The major development in the Knorr pyrrole synthesis has been access to the amine component. For example, use of preformed diethyl aminomalonate with 1,3-diketones affords much higher yields of pyrroles 14. Reaction of 6-dicarbonyl compounds with hydroxylamine 0-sulfonic acid gives pyrroles 15 in one step. Weinreb a-aminoamides have found use in the Knorr pyrrole synthesis of a wide variety of pyrroles 16. °... 

Diethyl aminomalonate, from reduction of diethyl isonitrosomalonate, 40, 2 ... 

Reagent and conditions i, diethyl chloromalonate, DMF ii, DBN, MeOH iii, AcOH, H2O iv, AcONa, diethyl aminomalonate HCI, MeOH/H20 v, MeONa, MeOH vi, 2,5-dimethoxyTHF, 4-chloropyridine hydrochloride, dioxane vii, pyrrolidine viii, (a)POCI3, (b) 10%NaOH... 

A facile synthesis of 5-substituted 3-aminopyrrole-2-carboxylates has been developed wherein condensation of diethyl aminomalonate with a-cyano ketones 46 was facilitated by prior formation of the p-toluenesulfonyl enol ether 47 <00JOC2603>. Addition of the amine component is followed by cyclization and decarboxylation to afford the pyrroles 48. 

Diethyl acetylenedicarboxylate as di-eneophile, 40, 86,87 Diethylamine, condensation with tri-chloroacetyl chloride, 41, 21 Diethyl aminomalonate, from reduction of diethyl isonitrosomalonate, 40, 24... 

Diethyl aminomalonate reacts with 1,3-diketones in boiling acetic acid to the corresponding pyrrolecarboxylates 11 (87JOC3986). From N-ac t-amidomalonate and acroleins, pyrrolidines were prepared and they were further transformed into functionalized pyrroles, which are a part of the antibiotic lyncomycin and an antimalarial agent (67JA2459 72JMC1255). 

A new synthetic method for 4-hydroxyproline was devised from N-acylated diethyl aminomalonate. In the first step this reacts with acrolein in the presence of a base to give 12 (90JHC507). 

Acylaminomalonic esters and related reagents are widely used for the synthesis of a-amino acids. The method differs from those syntheses already discussed in that the amino group is incorporated into the system from the outset. A popular reagent is diethyl acetamidomalonate (35). The acetamido group can readily be introduced into the reactive methylene position in diethyl malonate by first converting the latter into the hydroxy-imino derivative (33) by reaction with nitrous acid or an alkyl nitrite (cf. Section 4.2.7, p. 413). This derivative is then reduced catalytically to diethyl aminomalonate (34) which is acetylated using acetic anhydride. 

A mixture of 2.0 g of l-(2-nitro-3-chlorophenyl)-l,3-butanedione, 1.9 g of diethyl aminomalonate, 1.5 ml of absolute ethyl alcohol and two drops of piperidine was refiuxed for 5 hours. After cooling, the reaction mixture was allowed to stand and then crystals were separated. The crystals were collected by filtration and then dried to obtain 2.5 g of colorless crystals. The crystals were recrystallized from a mixed solvent of benzene and ether to obtain diethyl N-[ 1-methyl-3-(2-nitro-3-chlorophenyl)-3-... 

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