Condensation of diphenylsulfonium cyclopropylide with diary] and arylalkylimines generates azaspiropentanes. Solvolyse in methanol of 1,2-diphenylazispiropentane gives the adduct cyclopropane, whereas anhydrous hydrochloric acid treatment gives cyclobutanimine which may be hydrolysed in aqueous acid into cyclobutanone.
IR and NMR studies have been performed on 1,3 primary secondary diols. It has been shown that these compounds are in chelated forms. NMR studies are also performed on dioxanes having Me, Et, iPr or tBu substituents on position 4 and Me on position 5. They lead to chemical shifts in accordance with these obtained by empirical calculation.
Benzimidazolotriazines, pyrazolotriazines and triazolotriazines are synthetized by condensation reaction of N-acyl and N-ethoxycarbonyl iminoesters on 2-amino-benzimidazol,3-amino-4-methyl-5-phenyl pyrazol and 3-amino-1,2,4 triazol.
M.T. Kaddachi, B. Hajjem, B. Baccar
Addition of Girard T reagent on cyclohaxanone in acidic medium is an equilibrinne reaction having a constant K which is equal to the ratio of formation constant (kf) over decomposition constant of the product (kd). Measuring and analysing kinetical constants allow to point out the occurrence of an acid catalysis for that reaction in water at 25.0°C in chlorhydrate, acetate, formiate and chloroacetate buffer solutions. Bronsted constants are also calculated for the formation (α = 0.25) and decomposition of the product (α = 0.20), and equilibrium constant is found to be equal to K = kf / kd = 114 ± 3.
L. Loubaki, T. Silou
Low motions E.S.R. studies in V2O5, nH2O at low temperature (77 to 300 K) allow for the distinction between two types of water: the first one, is an inter layer type and leaves the material giving ice, and the second one consists in tightly bonded water molecules which form two layers per V2O5 groups.
N. Gharbi, J. Livage
Six samples of the clay deposit found near Gabes (Tunisia) were mineralogically characterized. The clay is a sodic bentonite containing near 20% impurities (quartz, calcite, kaolinite). The clay fraction is an irregular smectite-illite interstratified mineral containing 12 to 24% illite. The smectitic fraction has a dominant beidellitic character.
E. Srasra, N. Kebir-Ariguib, F. Ayedi, F. Bergaya, H. Van Damme
Thermolysis of N-ethoxycarbonylazidines normally affords allyl carbamates. In the case of 1-6 unsubstituted N-ethoxycarbonyl 7-aza bicyclo [4-1-0] heptanes a different reaction pathway leading to vinyl carbamates is observed.
R. Ben Cheikh, R. Chaabouni, P. Mison