Isocyanatocarboxylic acid

The imidazolide group at the amino end of an amino acid is as reactive toward nucleophiles as the imidazolide group at the carboxylic end of an amino acid. If an N-protected amino acid is selected as nucleophile, this method can also be used for peptide synthesis. The amino-activated amino acids, for example N-( 1 -imidazolylcarbonyl)-amino acid esters, are prepared from a-isocyanatocarboxylic acids and imidazole. 

Amino-4H-3,l-benzoxazin-4-ones from o-isocyanatocarboxylic acid chlorides... 

Chiral y-amino-acids (e.g. 180) have been prepared from the corresponding optically active /8-amino-acids by the addition of one carbon atom using the Arndt-Eistert reaction.w-Amino-acids are available from cyclic anhydrides by treatment with stannyl azide (to give an w-isocyanatocarboxylic acid) followed by addition of an alcohol. In contrast to simple enamines, oxidation of N-acyl-a-aminocrotonates with thallium nitrate leads to the corresponding a/8-dimethoxy derivatives. 

Phosgene/hydrogen chloride Isocyanatocarboxylic acid chlorides from aminocarboxylic acids... 

N,N,0-tris(carbamyl)-hydroxylamines 26, 293 Isocyanatocarboxylic acid esters... 

Trimethylchlorosilane/triethylamine Isocyanatocarboxylic acid silyl esters from aminocarboxylic acids via aminocarboxylic acid silyl ester hydrochlorides and carbophenoxyaminocarboxylic acid silyl esters... 

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