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Amidomalonate

Problem 26.6 What alkyl halides would you use to prepare, the following a-amino acids by the amidomalonate method ... [Pg.1026]

Serine can be synthesized by a simple variation of the amidomalonate method using formaldehyde rather than an alkyl halide. Plow might this be done ... [Pg.1054]

Amidomalonate synthesis (Section 26.3) A method for preparing a-amino acids by alkylation of diethyl amidomalonate with an alkyl halide. [Pg.1235]

Using esters instead of acids reduces the rate of formation of lactones and gives rise to trapping by solvent as well as the formation of overall diene substitution products. Oxidation of amidomalonic ester 57, for example, yields as major products the acetic acid trapping product 58 and the diene substitution product 59, but only 5% of lactone 60 (equation 26). The oxidation of the initially formed amidomalonic ester radical, of increased importance in this case due to the amide substituent, could be largely reduced through addition of sodium acetate or trifluoroacetic acid, which are known to reduce the oxidation potential of the Mn(III) acetate. [Pg.645]

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). [Pg.12]

A tetrahydropyrido[3,4-/)]pyrazine nucleus was constructed from 2,3-dimethylpyrazine 687 by chlorination with A-chlorosuccinimide (NCS) to give 2,3-bis(chloromethyl)pyrazine 688, followed by cyclization with diethyl acet-amidomalonate to pyridopyrazine 689. Hydrolysis and decarboxylation of 689 in hydrochloric acid, then esterification by action of thionyl chloride in methanol gave methyl 5,6,7,8-tetrahydropyrido[3,4-. ]pyrazine-7-carboxylate hydrochloride 690 (Scheme 32) <2003BMC433>. [Pg.832]

The synthesis of racemic Tic (rac-33) can be accomplished by alkylation of acet-amidomalonates in a reasonable yield (Scheme 15). Racemic Tic can then be subjected to resolution using menthol.1[7 ] This route is a good alternative for synthesizing both enantiomers of Tic. [Pg.24]

The two examples illustrative of the section, however, involve alternative procedures for introducing the required substituent into the a-position of the acet-amidomalonate reagent. In the first (Expt 5.183) the hydroxymethyl group is introduced by a simple base-catalysed condensation with formaldehyde subsequent hydrolysis and decarboxylation yields serine (R = CH2OH). In this case, acidic conditions are preferred for the final hydrolytic stage, and the use of a weakly basic ion exchange resin to obtain the halide-free amino acid from a solution of its hydrochloride is described. [Pg.749]

In the amidomalonate synthesis, shown above, an alkyl halide RX is converted to RCH(NH3+)CC>2H. Choose an alkyl halide that completes the structure of the target amino acid. [Pg.724]

Methyls are trans in NN, PP cis in OO, QQ, RR (b) NN is resolvable. 22. See p. 1087. 23. (a) Ethyl acetate (b) methacrylic acid (c) phenylacetamide. 24. (a) /i-Propyl formate (b) methyl propionate (c) ethyl acetate. 25. SS, benzyl acetate TT, methyl phenylacetate UU, hydrocinnamic acid, PhCH2CH2COOH. 26. Ethyl anisate. 27. VV, vinyl acetate. 28. (a) Ethyl adipate (b) ethyl ethylphenylmalonate ethyl aoet-amidomalonate. [Pg.1199]

Problem 26.9 What alkyl halides would you amidomalonate method ... [Pg.1104]

A more general method for preparation of a-amino acids is the amidomalonate synthesis, a straightforward extension of the malonic ester synthesis (Section 22.7). The reaction begins with conversion of diethyl acetamidomalonate into an eno-late ion by treatment with base, followed by 5 2 alkylation with a primary alkyl halide. Hydrolysis of both the amide protecting group and the esters occurs when the alkylated product is warmed with aqueous acid, and decarboxylation then takes place to yield an a-amino acid. For example, aspartic acid can be prepared from ethyl bromoacetate, BrCH2C02Et ... [Pg.1026]

Simplest of all the laboratory methods, in concept, are those general methods based on the alkylation of glycine derivatives shown in Scheme 6.3, particularly 2-acyl-amidomalonate esters (1), Schiff bases (2), oxazol-5(4H)-ones (alias azlactones , 3) and piperazin-2,5-diones (4). [Pg.123]


See other pages where Amidomalonate is mentioned: [Pg.552]    [Pg.1026]    [Pg.1285]    [Pg.1286]    [Pg.146]    [Pg.552]    [Pg.720]    [Pg.720]    [Pg.747]    [Pg.749]    [Pg.254]    [Pg.3888]    [Pg.1026]    [Pg.1026]    [Pg.1026]    [Pg.552]    [Pg.1084]    [Pg.1084]    [Pg.1104]    [Pg.1026]    [Pg.552]    [Pg.1084]    [Pg.3887]   
See also in sourсe #XX -- [ Pg.129 ]




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Amidomalonate synthesis

Amino acid amidomalonate synthesis

Esters amidomalonic

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