Alain Gueiffier

Synthesis and antiviral activity of 3-substituted imidazo[1,2-a]pyridines.

A series of 3-substituted imidazo[1,2-a]pyridines wa synthesized as potential antiviral agents. Compound 10b and, to a lesser extent, 10c showed activity against both TK+ and TK− strains of varicella-zoster virus.

SRN1 reactions in imidazo [1, 2-a] pyridine series

2-Chloromethyl-3-nitroimidazo[1,2-a]pyridine is shown for the first time to react with 2-nitropropane salts by an SRN1 mechanism to give excellent yield of isopropylidene derivative formed from the C-alkylation product by loss of nitrous acid.

Synthesis of Pyrroloquinoline and Pyrrolonaphthyridine by an Intramolecular Cyclisation Reaction

4-Methylthiopyrrolo[1,2-a][1,8]naphthyridine and pyrrolo[1,2-a]-quinoline were prepared by an intramolecular cyclisation in acidic media of 1-methylsulfinyl-1-methylthio-2-[3-(2-(1-pyrrolyl)pyridin or phenyl)]ethylene

Synthesis and Antiviral Activity of 2 and 3-Substituted Imidazo[1,2-a]pyrimidine

Abstract Synthesis of acyclo-C-nucleoside derivatives in the imidazo[1,2-a]pyrimidine series was reported. None of the evaluated compounds showed appreciable antiviral activity.

Reactivity of phenyllithium toward bridgehead nitrogen heterocycles

The reactivity of phenyllithium toward some bridgehead nitrogen heterocycles was investigated. Imidazo[1,2-a]pyridine gave the substitution, while other series gave addition reactions. In addition, the ring opening derivative was obtained in imidazo[1,2-c]quinazoline series

REACTIVITY OF METHYLLITHIUM TOWARDS BRIDGEHEAD NITROGEN HETEROCYCLES

Reactivity of methyllithium towards some bridgehead nitrogen heterocycles was investigated. In a previous communication we have reported the reactivity of phenyllithium on some polyazaindenes (1). The results obtained prompted us to investigate other bases. Among alkyllithium derivatives, methyllithium was attractive because the reactivity of this reagent toward bridgehead nitrogen heterocycles seemed uninvestigated. Methyllithium adds to pyridine or quinoline to give 4-methyl-l,4-dihydropyridine or quinoline (2) while Peake and coworkers, obtained 2-methylquinoline by the action of methyllithium and iodine for aromatization (3) . Recently Shiotani and coworkers (4), using methyllithium-lithium bromide complex at -78°C, reported the ring opening of furan cycle in 3-bromofuropyridines to give ethynylpyridinol and unsubstituted heterocycle. In this work, we report the reaction of methyllithium on imidazo[l,2a]pyridine (A), imidazo[l,2-a]pyrimidine (B) , imidazo[l,2-a]pyrazine (C) , imidazo[1,2-c]quinazoline (D), and imidazo[1,2-a][1,8]naphthyridine (E) in ether at 20°C. A X = CH, Y=CH Β X = N, Y = CH C X=CH, Y = N οσ

Synthesis of original pyrrolonaphthyridines by 1,3-dipolar cycloaddition reactions of naphthyridinium dicyanomethylides with dimethyl acetylene-dicarboxylate

The pyrrolo[2,1-f][1,6]naphthyridine, pyrrolo[1,2-a][1,8]- and [1,5]naphthyridines along with their corresponding 2,3- and 1,2-dihydrocompounds are synthesized from naphthyridinium dicyanomethylides and dimethyl acetylenedicarboxylate

Inhibitory effects on platelet aggregation and cyclic AMP phosphodiesterase of azaindolizine-type compounds: Structure—activity relationships and molecular modelling

Abstract Grassy, G., Stigliani, J.-L., Szefner, J., Gueiffier, A., Teulade, J.-C., Chapat, J.-P. and Adam, Y., 1993. Inhibitory effects on platelet aggregation and cyclic AMP phosphodiesterase of azaindolizine-type compounds. Structure-activity relationships and molecular modelling. Chemometrics and Intelligent Laboratory Systems, 20: 71–84. This paper deals with the synthesis and biological activities of aryl-2 imidazo[1,2-a]pyridines and pyridines. These compounds are valued as inhibitors of cyclic AMP phosphodiesterase (PDE) derived from beef heart and as inhibitors of human platelet aggregation. The most attractive in this series, compounds 13a and 15a, are ten times more potent than aspirin on arachidonic acid induced platelet aggregation. They also exhibit significant activity as inhibitors of phosphodiesterase. Analysis of these azaindolizine-type compounds by molecular modelling techniques suggests spatial and electronic similarities with other classes of PDE inhibitors.