- Reaction of thiourea dioxides with amines
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The reaction mechanism of thiourea dioxides with ammonia and primary aliphatic amines involves direct nucleophile (ammonia or amine) reactions with thiourea dioxides, followed by dissociation of the resulting adduct to form the sulfoxylate ion. 2004 MAIK "Nauka/Interperiodica".
- Makarov,Kudrik,Terskaya,Davydov
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p. 1383 - 1385
(2007/10/03)
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- Synthesis and Structure-Activity Relationships of N,N'-Di-o-tolylguanidine Analogues, High-Affinity Ligands for the Haloperidol-Sensitive ? Receptor
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With an eye toward the development of novel atypical antipsychotic agents, we have studied the structure-affinity relationships of N,N'-di-o-tolylguanidine (DTG, 3) and its congeners at the haloperidol-sensitive ? receptor.A number of DTG analogues were synthesized and evaluated in in vitro radioligand displacement experiments with guinea pig brain membrane homogenates, using the highly ?-specyfic radioligands -3 and -(+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine and the phencyclidine (PCP) receptor specyfic compounds -N-piperidine and -(+)-5-methyl-10,11-dihydro-5H-dibenzocyclohepten-5,10-imine.The affinity of N,N'-diarylguanidines for the ? receptor decreases with increasing steric bulk of ortho substituents larger than C2H5.Hydrophobic substituents are generally preferred over similarly positioned hydrophilic ones.Furthermore, electroneutral substituents are preferred over strongly electron donating or withdrawing groups.Significant binding to the ? receptor is usually retained as long as at least one side of the guanidine bears a preferred group (e.g. 2-CH3C6H5).Replacement of one or both aryl rings with certain saturated carbocycles (e.g. cyclohexyl, norbornyl, or adamantyl) leads to a significant increase in affinity.By combining the best aromatic and best saturated carbocyclic substituents in the same molecule, we arrived at some of the most potent ? ligands described to date (e.g.N-exo-2-norbornyl-N'-(2-iodophenyl)guanidine, IC50 = 3 nM vs -3).All of the compounds tested were several orders of magnitude more potent at the ? receptor than at the PCP receptor, with a few notable exceptions.This series of disubstituted guanidines may be of value in the development of potential antipsychotics and in the further pharmacological and biochemical chracterization of the ? receptor.
- Scherz, Michael W.,Fialeix, Michelle,Fischer, James B.,Reddy, N. Laxma,Server, Alfred C.,et al.
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p. 2421 - 2429
(2007/10/02)
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- Synthesis of Guanidino-1,3,5-triazines Using DMF
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2,4,6-Triguanidino-1,3,5-triazine and 2,4,6-tris(3-methylguanidino)-1,3,5-triazine were synthesized in 42 and 52percent yields, respectively, by the cyclotrimerization of cyanoguanidine and 1-methyl-3-cyanoguanidine using DMF as a solvent in the presence of hydrogen chloride. 1-Phenyl-3-cyanoguanidine, 1,2-dimethyl-3-cyanoguanidine, and 2-imidazolidinylidenecyanamide, however, were cyclodimerized to the corresponding guanidino-1,3,5-triazines in a similar manner.
- Iio, Kokoro,Ichikawa, Eiichi
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p. 2735 - 2736
(2007/10/02)
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- Bicyclic amidines
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New amidine/isocyanate adducts are particularly useful as catalysts for hardening epoxy resins, in particular pulverulent coating compositions based on epoxy resins. New bicyclic amidines are excellent starting materials for manufacturing these amidine/isocyanate adducts.
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