Aminodicarboxylic acid

Polyimides (PI) are polycondensation products (1) prepared from derivatives of tetracarboxylic acids and primary diamines (1—5). Descriptions of self-polycondensation polymers (2) based on aminodicarboxylic acid derivatives are also found in the literature (6—9). 

The diversity of the Ugi-MCR mainly arises from the large number of available acids and amines, which can be used in this transformation. A special case is the reaction of an aldehyde 9-26 and an isocyanide 9-28 with an a-amino acid 9-25 in a nucleophilic solvent HX 9-30 (Scheme 9.5). Again, initially an iminium ion 9-27 is formed, which leads to the a-adduct 9-29. This does not undergo a rearrangement as usual, but the solvent HX 9-30 attacks the lactone moiety. Such a process can be used for the synthesis of aminodicarboxylic acid derivatives such as 9-31 [3, 30],... 

More proper analogues of cystine than the a-aminodicarboxylic acids are a,a -diaminodi-carboxylic acids that contain all the functional groups of cystine as well as the correct length of the Ca to Ca spacer. For this purpose first synthetic approaches were based on the use of cystathionine as the monocarba-analogue14 36 which were then followed by the use of dicarba-analogues. 

Oxidation of 2-aminoquinolin-4-ol by potassium permanganate furnishes a mixture of quin-azolin-4(.3//)-one (21%) and quinazoline-2,4(lFf,3F/ )-dione (15%). The formation of the quinazoline ring apparently involves an initial oxidative fission of the N3-C4 double bond of the quinoline, followed by a recyclization of the resulting aminodicarboxylic acid." " ... 

Intermediate 4-nitrobenzyl ester protection has been used in the efficient syntheses of A -Z-protected aminodicarboxylic acid co-tert-butyl estersP via terf-butylation of Z-Asp-ONbz followed by selective saponification of Z-Asp(OtBu)-ONbz.P ... 

Without additional reagents N-a-Aminodicarboxylic acid imides from azomethines... 

Aminodicarboxylic acids s. a-Aminomethyl-a-dicarboxylic acids a-Aminodicarboxylic —... 

Thionyl chloride trifluoroacetic acid a-Aminodicarboxyiic acid anhydrides from c(-aminodicarboxylic acids... 

N-Aminodicarboxylic acid imides from dicarboxylic acid imides via dicarboxylic acid amide hydrazides... 

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