N-(2-benzimidazoyl) imidate type 1 react with isocyanates and isothiocyanates to give the corresponding [1, 2-a] benzimidazo-1,3,5-triazin-4-one and [1, 2-a] benzimidazo-1,3,5-triazin-4-thione in 60-75 % overall yield.
R. Abderrahim, B. Hajjem, B. Baccar
A search for increasing progestin activity has led to the synthesis of the 17α-acetoxy-6,21-dimethy1-3,20-dioxo-19- norpregna-4,6-diene. This new compound has been obtained from the 19-norandrostenedione which was subjected to, a Wittig reaction with Ph3P=CHEt, followed by oxidation of Δ-17(20) to 17α-OH and 20-oxo by OsO4 and triethylamine N-oxide hydrogen peroxide, and finally elaboration in to the 6-methyl-4,6-diene-3-one according to know methodologies.
M.N. Nasraoui, A. Piasco, C. Tchernatinsky
The 1,3-dipolar cycloaddition of diazo-2 propane (DAP) with diactivated dissymetric acetylenes has enabled us to synthesise in good yield homologous 3H-Pyrazoles with an acetyl group as substituent on C4 or C5. The synthesis of the starting acetylenes was carried out satisfactorily.
3-chloro-2-phenyl-3-trifluoromethylacrolein reactivity towards various nucleophiles has been studied. Depending on solvent and reagent several mecanisms are involved: 1,2 addition followed or not by reduction or elimination and β-substitution followed or not by 1,4 addition.
A. Selmi, M.M. El Gaied, G. Alvernhe
The kinetics of crystallization of calcium sulfate dihydrate has been studied at 30°C, in magnesium poisoned solutions by constant composition method. The inhibitory effect of the magnesium ions on the rate of crystallization has been attributed to their adsorption at particular sites.
S. Ghorbel, H.F. Ayedi, J.-C. Heughebaert
The behaviour of the Porous Percolated Pulsated Electrode (3PE) being similar, either to that of a plag-flow reactor or to that of a perfectly-stirred reactor. Expressions of intensity through the cell and of voltage drop are established for both working modes. We show that operating a 3PE reactor allows the use of a granular matrix up to twice as high as that of a fixed-bed reactor.
A. Gadri, A. Ratel, G. Lacoste
The presence of essential amino-acids in the leaves of vegetables is an important factor when appreciating the quality of these vegetables. The study of free amino-acids in vegetal species with edible leaves appears then to be important in the choice of a vegetable. This is the purpose of this article which is about the quantitative analysis of free amino-acids in leaves of twelve edible plants.