No abstract

Irradiation. -Microwave irradiation is found to increase yields and greatly shortens reaction times. -(CHAUHAN, S. S.; SHARMA, A.; SAINGAR, S.; JOSHI*, Y. C.; J. Indian Chem. Soc. 82 (2005) 11, 1016-1018; Dep. Chem., Univ. Rajasthan, Jaipur 302 004, India; Eng.) -C. Oppel 22-124

Some 3,5-disubstituted pyrazoles derivatives (2a-2f) have been synthesized.Their structure were confirmed by elemental analysis, IR, 'H NMR, l3 C NMR and MS spectral studies.

An efficient synthesis of novel 2,3,4-trisubstituted 1,5-benzothiazepines (4a-e) incorporating the sulfonyl group is described. Compound (4a-e) was synthesized by the reaction of 3-(1,4-dioxane-6-sulfonyl)-2,4-dimethyl/4-methyl-2-phenyl/2,4-diphenyl/2-ethoxy-4-methyl/2,4-diethoxy propane-1,3-dione (3ae) with 2-aminobenzenethiol with ZnOnanoparticles/pyridine. Formation of compound (3a-e) was achieved by the reaction of 1,4-dioxane-6-sulfonyl chloride (1) with 2,4-dimethyl/4-methyl-2-phenyl/2,4-diphenyl/2-ethoxy-4-methyl/2,4-diethoxy propane-1,3-dione (2a-e). The benzothiazepines (4a-e) obtained were purified by column chromatography (benzene: CHCl3, 40:60, 30:70, 20:80, 10:90) and crystallized from methanol. The purity of the compounds was checked by TLC using (CHCl3: CH3OH, 9:1) as the mobile phase. The structure of the compounds has been established by elemental, IR, 1H NMR, 13C NMR and Mass spectral analyses. Frontier molecular orbitals of the title compounds have been studied in the ground state speculatively. The reactivity of a molecule using diverse descriptors such as softness, electrophilicity, electronegativity, HOMO-LUMO energy gap is calculated additionally discussed.

The transient viscosities of sterically stabilized alumina suspensions with different degrees of aggregation were measured at low viscous flows in a Couette viscometer. The well‐dispersed suspensions showed an increase in viscosity under a constant applied shear while the flocculated suspensions showed just the opposite behaviour. The drifts in the viscosity of the well‐dispersed suspensions show strong features of shear‐induced particle migration. However, experimental observations strongly indicate that the observed viscosity profiles of these suspensions are resultant of the competitive processes of shear‐induced particle migration and shear rejuvenation. The drifts in viscosity of the well‐dispersed suspension could be correlated to the degree of aggregation present in the suspension. On the other hand, the viscosity profiles of the flocculated suspensions showed characteristic shear rejuvenation behaviour. © 2016 Curtin University of Technology and John Wiley & Sons, Ltd.