Guanidine derivatives

Some Gua lesions are characterized by a guanidine residue that can be detected spectrophotometrically using l,2-naphthoquinone-4-suphonate as the reagent (Kobayashi et al. 1987). The resulting product is shown in reaction (19). 

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Ultraviolet spectral comparisons indicate that structure 107 predominates over 108 when R = H or OH, but that 107 is the predominant form when R = aryl. - Similarly, 109 predominates over 110 by a large factor when R = H, OH, or Me, and by a smaller factor when R is a higher alkyl group, but 110 predominates when R is an aryl group. (For a discussion of guanidine derivatives corresponding to 110, see reference 110.)... 

Treatment of 8-azidomethylperhydropyrido[l,2-c]pyrimidin-l-one 157 with methyl triflate and catalytic hydrogenation of the azide group led to the formation of tricyclic guanidine derivative 158 (01JA8851). Hydroxy group of 149 was protected with methoxymethyl chloride, and the p-methoxybenzyl protecting group (PMB) was eliminated by treatment with DDQ. 

Little progress has been made in the field of Group 15 metal amidinate and guanidinate derivatives. Only very recently some exciting results have been reported which demonstrate that this area may hold some real surprises and merits further exploration. It was found that amidinato ligands are capable to stabilize novel amidodiarsenes. Reduction of the four-membered ring As(III)... 

Mono(guanidinate) complexes of lanthanum and yttrium have been synthesized as illustrated in Scheme 58.The lanthanum compounds were made starting from La[N(SiMe3)2]3 and dicyclohexylcarbodiimide. Both mono (guanidinate) derivatives are monomeric in the solid state with a four-coordinate La center. ... 

Diamines can also react with only one equivalent of isothiocyanate to form bi-functionnal amine-thiourea ligands 59-68% yields obtained for several alkyl isothiocyanates. However, reaction of phenyhsocyanate with 1,2-diamines could also lead to the formation of the guanidine derivative by cyclisation and elimination of H2S (Scheme 4) [42,43]. 

Moreau and co-workers have also prepared (ll ,2K)-l,2-diaminocyclo-hexane amino-urea and thiourea derivatives [43]. Diphenylethylenediamine-substituted monothioureas are more stable than the cyclohexyldiamine counterpart, but they can also rearrange to guanidine derivatives, especially at high temperature or in the presence of metal [43]. Under the same conditions, thioureas also rearrange to guanidines in the presence of amines. Selective formation of substituted guanidines from thiourea derivatives of diaminocy-clohexane or diphenylethylenediamine were also reported in a recent paper from Ishikawa [44]. 

Solvent Influences on Oxidation and Nuclearity of Cold Guanidinate Derivatives 21... 

H.E., Irwin, M.D., Perez, L.M. and Fadder, J.P. Jr (2007) Dinudear and Tetranudear Gold—Nitrogen Complexes. Solvent Influences on Oxidation and Nudearity of Gold Guanidinate Derivatives. Inorganic Chemistry, 46, 11165-11172. 

Hydrogen-Bonded Supramolecular Chain and Sheet Formation by Coordinated Guanidine Derivatives... 

Primary amines with various complex groups R can be transformed (amidinylation) into guanidine derivatives by reaction with 3,5-dimethylpyrazole-l-carboxamidinium nitrate in the presence of a tertiary amine such as diisopropylethyl- or triethylamine in THF or DMF [4H6] see also reference [7]. 

Fig. 10.4 Structure of guanidine derivatives and compounds structurally similar to guanidine. ...

Diethyl N-(4-Aminophenyl)aminomethylenemalonate (167, R = H) was reacted with N, Af -bis(methoxycarbonyl)-5-methylisothiourea in the presence of p-toluenesulfonic acid in boiling methanol for 4 hr to afford the guanidine derivative (1590) in 50% yield. The guanidine (1590) was oxidized in chloroform with lead tetraacetate to the quinoline diimine (1591), which cyclized to 1592. After methanolysis, the 2-(methoxycarbon-ylamino)benzimidazole derivative (1593) was obtained in 41% yield [86JCR(S)161]. 

Other groups, including azide, peroxide, diazophenols, and nitrogen-rich compounds derived from guanidine derivatives. 

Synthetic guanidine derivatives have been used successfully in the treatment of a variety of diseases, but the major success has undoubtedly been their exploitation as antihypertensive drugs. Guanethidine has still not been displaced. 

The more usual methods which have been employed for testing guanidine derivatives as potential antihypertensive drugs depend on detecting some form of interference with the sympathetic nervous system. This.subject has also been reviewed recently in considerable detail [202], and only those methods which have been, or could be, widely applied to elucidating structure-activity relationships are described here. 

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