Alkylthio Side Chains Research Articles

Synthesis of non-immunosuppressive cyclophilin-Binding cyclosporin A derivatives as potential anti-HIV-1 drugs

Original cyclosporin A (CsA) derivatives bearing various alkylthio side chains at the sarcosine residue 3 (R configuration) and for the most potent and selective compounds a 4′-hydroxyl group at the Me-Leucine residue 4 were prepared in one or two steps from commercially available CsA. The [2-(dimethyl or diethylamino)-ethylthio-Sar]3-[(4′-OH)MeLeu]4-CsA derivatives 3k and 3l displayed potent in vitro anti-HIV-1 (IC50 ∼46 nM) and low immunosuppressive activities (IC50≥1500 nM).

Glasses of new 2,3,9,10,16,17,23,24-octasubstituted phthalocyanines forming thermotropic and lyotropic discotic mesophases

The synthesis and mesogenic properties of a new class of liquid crystalline metal-free and metalated phthalocyanines with different numbers of alkylthio side chains are presented. The effect of the substitution pattern in a series of differently octasubstituted phthalocyanines on the width and order of the thermotropic mesophase is investigated. The exchange of the alkylthio groups from chlorine atoms alters the mesophase width and the melting behaviour. Glassy phthalocyanines, without any tendency to crystallize, can be synthesized in this way. Furthermore, mixtures of differently 4,5-disubstituted benzenedicarbonitriles are tetramerized statistically to the corresponding mixtures of substituted phthalocyanines. The effect of decreasing symmetry at the molecular level on the properties of the liquid crystalline materials has been investigated. Highly oriented columnar systems can be obtained with these mixtures. For all compounds containing less than eight alkylthio groups, lyotropic mesomorphism in hexadecane solution is also found.

Synthesis and in vitro activity of 1 beta-methyl C-2 quaternary heterocyclic alkylthio carbapenems.

New 1 beta-methylcarbapenems having various (substituted) quaternary heterocyclic alkythio groups at the C-2 position were synthesized and tested for antibacterial activity and renal dipeptidase susceptibility. Compounds having the 1 beta-methyl substituent were found to possess an increased stability to the enzyme. In addition, combination of the 1 beta-methyl substituent and the C-2 quaternary heterocyclic alkylthio side chain generated compounds with excellent antipseudomonal activity and improved stability toward hydrolysis by renal dipeptidase.

Synthesis and biological activities of 2,3-dimethyl-1,4-benzoquinones having alkylthio and arylthio side chains.

New 2, 3-dimethyl-1, 4-benzoquinones having an alkylthio or arylthio side chain at the 5-position and two alkylthio side chains at the 5-and 6-position were synthesized as possible antimetabolites of coenzyme Q. These compounds were tested for inhibition of coenzyme Q in mitochondrial succinoxidase and reduced nicotinamide adenine dinucleotide (NADH) -oxidase systems, and were found to show greater inhibition of the NADH-oxidase system than of the succinoxidase system. 5, 6-Di-octylthio-2, 3-dimethyl-1, 4-benzoquinone showed greater inhibitory activities than 5-alkylthio-2, 3-dimethyl-1, 4-benzoquinones. 5-Arylthio-2, 3-dimethyl-1, 4-benzoquinones showed potent inhibitory activities towards both enzyme systems.

Synthesis and phase-transfer property of macrocyclic polythiaether sulphoxides

New macrocyclic polythiaethers with alkylthio side chains have been prepared in good yields starting from 2,6-dithiaspiro[3.3]heptane. The corresponding polysulphoxides were also prepared by the general oxidation method. The macrocyclic polythiaether sulphoxide with benzylsulphinyl side chains was found to be an excellent phase-transfer catalyst which promotes alkylation of benzyl methyl ketone with alkyl halides in a liquid-liquid two-phase system.

ChemInform Abstract: SYNTHETIC APPLICATIONS OF INTRAMOLECULAR INSERTION IN ARYLCARBENES. II. O‐ALKOXY‐, DIALKYLAMINO‐ AND ALKYLTHIOPHENYLCARBENES

AbstractAus o‐Alkoxy‐, o‐Dialkylamino‐ und o‐Alkylmercapto‐benzaldehydtosylhydrazon‐Na‐Salzen werden in der Gasphase Carbene erzeugt und unter vermindertem Druck der Pyrolyse bei 250, 500 und 750°C unterworfen.

Synthetic Applications of Intramolecular Insertion in Arylcarbenes. IV. o-Alkoxy-, Dialkylamino- and Alkylthio-1-phenylethylidenes

A series of 1-phenylethylidenes, substituted in the ortho-position by alkoxy, dialkylamino and alkylthio side chains containing up to three carbon atoms, has been generated in the gas phase and pyrolysed at 250-750�/0.05-0.30 mm. Carbene insertion to form five-membered heterocyclic rings predominates, with up to 20% Bamford-Stevens insertion, to give the styrenes; little or no formation of six-membered rings is observed. In cases where stereoselective insertion is possible, the trans-disubstituted heterocycle is formed preferentially, the selectivity being greatest in the case of dialkylamino substitution. The mechanisms involved are discussed in terms of transition state geometry.

Synthetic Applications of Intramolecular Insertion in Arylcarbenes. II. o-Alkoxy-, Dialkylamino- and Alkylthio-phenylcarbenes

A series of phenylcarbenes, substituted in the ortho-position by alkoxy, dialkylamino and alkylthio side chains containing up to three carbon atoms, has been generated in the gas phase and pyrolysed at 250-750�/0.05-0.20mm. Carbene insertion occurs in moderate to high yield to give the appropriate five-and six-membered heterocyclics, the former predominating. The regioselectivity of the carbene insertion (five-membered ring us six-membered ring) is highest in the case of the alkoxy and dialkylamino compounds, where six-membered-ring formation is relatively minor; in the case of the alkylthiophenylcarbenes, the selectivity in favour of the smaller ring is, by comparison, small. The reasons for this are discussed in terms of the geometry of the transition state and the donor capacity of the heteroatom.