Guanidation

N-(2-Chloroacetyl)-2,6-dimethy Ian Mine Lidoflazine Chloroacetyl guanide Guanethidine sulfate N-Chloroacetyl-N-phenyl-2,6-dichloro-aniline... 

The longest established silver(III) complexes are the red to brown bi-guanides, like the ethylene bis(biguanide) shown in Figure 4.14 persulphate oxidation of Ag+ in the presence of this ligand gives a silver(III) complex with essentially square planar coordination. 

Following the discovery of the antimalarial activity [148) of biguanides and quinoline derivatives, a variety of substituted quinolyl-b anides were synthesised [9, 42, 101, 188, 298, 303, 306, 428, 558, 583, 585) by these procedures. The production of a series of m.m-hexamethylenebi-guanides [724) illustrates the use of secondary amines in this synthesis. 

In the colorimetric estimation of p-phenethylbiguanide the plot of readings against concentration is found ipIO) to be a straight line at concentrations less than 10 W. Above this concentration, p-phenethylbi-guanide in solution deviates sharply from Beer s Law. It may be concluded that in the low concentration range over which Beers Law is valid, the compound exists in the monomeric state in aqueous solution. 

It is these reactions that are thought to provide some justification for equation (vii) [in Section VI B3] according to which p-phenethylbi-guanide in methanol exists to some extent as biguanidium methoxide. This being so, the reaction with alkyl halides is the nucleophihc displacement of the halogen ion by methoxide with formation of the methyl ether and the salt of the biguanide. 

Benzimidazolone guonylimide [called 1.2-o -Phenylen-biguanid or Benzimidazolyl-(2)-guanid ... 

Bis(functionalized) carbocycles via cyclization-borylsilylation, 11, 405 via cyclization-disilylation, 11, 401 via cyclization-stannylsilylation, 11, 402 Bis(guanidate) titanium(II) complexes, preparation and reactivity, 4, 268... 

Chloroacetyl guanide Lithium aluminum hydride Heptamethyleneimine Sulfuric acid... 

Dissolve the dried peptide sample (alkylated, guanidated) in 10 jxL of 0.1% aqueous TEA. 

Fig. 3. Automatically acquired MALDI-TOF/TOF MS/MS spectra of a tryptic peptide with m/z 1136.67 (upper panel) and of the same peptide after derivatization with SPITC at m/z 1393.11 (lower panel) using CHCA matrix. Whereas the unmodified peptide displays a rather complex spectrum with intense b- and y-ions in the same mass range, the lower spectrum shows a complete and dominant y-series allowing an easy manual sequence interpretation from m/z 189.09 to m/z 1178.32. The peptide sequence LRGGLC YLGK was deduced from the y-series with guanidated Lys (homoarginine = Flar) and N-terminal derivatization with SPITC. The cysteine residue was reduced and alkylated with DTT and iodoacetamide (M = 160.03 g/mol).

Skjelbo E, Mutabingwa TK, Bygbjerg I, et al. Chloro-guanide metabolism in relation to the efficacy in malaria prophylaxis and the 5-mephenytoin oxidation in Tanzanians. Clin Pharmacol Ther 1996 59 304-311. 

The availability of different types of amino groups allows a variety of reactions typical for amines which are suitable for the derivatization of PEI. Reaction partners can be aldehydes, ketones, alkyl halides, isocyanates and thioisocyanates, epoxides, cyanamides, guanides, ureas, acids, and anhydrides. The synthesis and chemical modification reactions of PEI will be discussed in the next sections. 

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