Amino hydrazides

EMazotization of an o-amino-hydrazide at low temperatures leads to the formation of a pyrazole ring (p. 241), but under more drastic conditions, a fused imidazolinone ring may be formed. 

Fewer methods are available to identify the C-terminal amino acid residue of a peptide. When the peptide is heated to 100°C (for about 12 hours) with hydrazine (NH2NH2), the amide bond of each residue is attacked and cleaved. The products are amino hydrazides. If tripeptide ala-val-leu (190) is heated with hydrazine, there are two amide bonds and the products are alanine hydrazide (191), valine hydrazide (192), and leucine (55). The C-terminal amino acid is not converted to the hydrazide because hydrazine reacts with the amide rather than with the free carboxyl group. 

This reaction forms the basis of one method of terminal residue analysis A peptide is treated with excess hydrazine in order to cleave all the peptide linkages One of the terminal amino acids is cleaved as the free amino acid and identified all the other ammo acid residues are converted to acyl hydrazides Which amino acid is identified by hydrazmolysis the N terminus or the C terminus ... 

Claisen ester condensation, 6, 279 Thiazolecarboxylic acid chlorides reactions, 6, 279-280 Thiazolecarboxylic acid hydrazides synthesis, 6, 280 Thiazolecarboxylic acids acidity, 6, 279 decarboxylation, 6, 279 reactions, S, 92 6, 274 Thiazole-2-carboxylic acids decarboxylation, S, 92 Thiazole-4-carboxylic acids stability, S, 92 Thiazole-5-carboxylic acids decarboxylation, S, 92 Thiazole-4,5-dicarboxylic acid, 2-amino-diethyl ester reduction, 6, 279 Thiazole-4,5-dicarboxylic acids diethyl ester saponification, 6, 279 Thiazolediones diazo coupling, 5, 59 Thiazoles, 6, 235-331 ab initio calculations, 6, 236 acidity, S, 49 acylation, 6, 256 alkylation, S, 58, 73 6, 253, 256 analytical uses, 6, 328 antifogging agents... 

Sulfobenzyl esters were prepared (cesium salt or dicyclohexylammonium salt, Na03SC6H4CH2Br, DMF, 37-95% yield) from A -protected amino acids. They are cleaved by hydrogenolysis (H2/Pd), or hydrolysis (NaOH, dioxane/water). Treatment with ammonia-or hydrazine results in formation of the amide or hydrazide. The ester is stable to 2 M HBr/AcOH and to CF3SO3H in CF3CO2H. The relative rates of hydrolysis and hydrazinolysis for different esters are as follows ... 

Aminosalicylic acid (5-amino-2-hydroxybenzoic acid) [89-57-6] M 153.1, m 276-280 , 283 (dec), pK 2.74 (CO2H), pK 5.84 (NH2). Cryst as needles from H2O containing a little NaHS03 to avoid aerial oxidation to the quinone-imine. The Me ester gives needles from C6H6, m 96°, and the hydrazide has m 180-182° (From H2O). [Fallab et al. Helv Chim Acta 34 26 1951, Shavel J Amer Pharm Assoc 42 402 1953.]... 

These hydrazides on treatment with nitrous acid are converted into azides, which with appropriate amino-alcohols, furnish ergometrine and its isomerides and analogues. The four pairs of stereoisomeric ergo-metrines and ergometrinines in the following list have been prepared in this way with l-( -(-)-)S-aminopropyl alcohol or its d-( —)-isomeride. 

As in 10-55 hydrazides and hydroxamic acids can be prepared from carboxylic esters, with hydrazine and hydroxylamine, respectively. Both hydrazine and hydroxylamine react more rapidly than ammonia or primary amines (the alpha effect, p. 445). Imidates, RC(=NH)OR, give amidines, RC(=NH)NH2. Lactones, when treated with ammonia or primary amines, give lactams. Lactams are also produced from y- and 5-amino esters in an internal example of this reaction. 

CN 4-pyridinecarboxylic acid 2-[3-oxo-3-[(phenylmethyl)amino]propyl]hydrazide... 

RN 2066-89-9 MF C7H7NO3 C,H,N30 MW 290.28 EINECS 218-183-2 CN 4-pyridinecarboxylic acid hydrazide mono(4-amino-2-hydroxybenzoate)... 

CN (25-cij)-benzoic acid [l-[4-[(3-amino-2,3,6-trideoxy-a-L-/>>xt>-hexopyranosyl)oxy]-l,2,3,4,6,l I-hexahydro-2,5,12-lrihydroxy-7-methoxy-6,1 l-dioxo-2-naphthacenyl]ethylidene]hydrazide... 

An auxiliary controlled enantioselective route to generate seven-membered ring lactams 75 used the a-alkylation of cyclic hydrazide derivatives 74. Initially, 6-chloro hydrazides 73,bearing the chiral information in the M-amino-pyrrolidine function underwent amidocyclization in the presence of a base. A subse-... 

L-alanylglycyl-L-cysteinyl-L-lysyl-L-asparaginyl-L-phenylalanyl-L-phenylalanyl-L-tryptophanyl-L-lysyl-L-threonyl-L-threonyl-L-cysteine 6-0-benzoyl-N-(benzyloxycarbonyl) methylamide 4,6-0-benzylidene-N-benzylidene-N-(benzyloxycarbonyl) methylamide N- (benzyloxy carbonyl) -N-(benzyloxycarbonyl)-, amide N-(benzyloxycarbonyl)-, hydrazide N-(benzyloxycarbonyl)-, methylamide N-(benzyloxycarbonyl)-, methyl ester N-(benzyloxycarbonyl)-L-alanyl-L-alanine methyl ester N-(benzyloxycarbonyl)-L-alanylglycine ethyl ester N-(benzyloxycarbonyl)glycyl-L-alanine methyl ester 3,4,6-tri-0-acetyl-2-amino-2-deoxy-N-(benzyloxycarbonyl)-, benzyl ester, hydrochloride... 

Much more important than these reactions, however, are the reactions of CDI and its analogues with carboxylic acids, leading to AAacylazoles, from which (by acyl transfer) esters, amides, peptides, hydrazides, hydroxamic acids, as well as anhydrides and various C-acylation products may be obtained. The potential of these and other reactions will be shown in the following chapters. In most of these reactions it is not necessary to isolate the intermediate AAacylazoles. Instead, in the normal procedure the appropriate nucleophile reactant (an alcohol in the ester synthesis, or an amino acid in the peptide synthesis) is added to a solution of an AAacylimidazole, formed by reaction of a carboxylic acid with CDI. Thus, CDI and its analogues offer an especially convenient vehicle for activation of... 

If the reactions are carried out with hydrazides like Z-NHNH2 or Z-Gly-NHNH2 instead of A-protected amino acids, the reaction products are called azapeptides [43]... 

The chemiluminescent properties of luminol (5-amino-2,3-dihydrophthalazine-l,4-dione) were first reported in 1928 by Albrecht1. Since that time, the chemiluminescence of luminol and related hydrazides has been studied extensively. 

TNBS has been used to measure the free amino groups in proteins (Habeeb, 1966 Kakade and Liener, 1969), as a qualitative check for the presence of amines, sulfhydryls, or hydrazides (Inman and Dintzis, 1969), and to specifically determine the number of s-amino groups of L-lysine in carrier proteins (Sashidhar et al., 1994). 

AMCA-Hydrazide 7-Amino-4-methylcoumarin-3-acetyl hydrazide MW 247. 1 Excitation = 345 nm Emission = 440-460 nm... 

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