Amorphous sulfated zirconium hydroxide was promoted with iron or manganese via the incipient wetness technique, to give 0.5–3.5 weight% promoter in the final catalyst. An exothermic reaction during the calcination temperature ramp (to 823 or 923 K) leads to a rapid overheating (“glow”) of the sample. XRD shows that crystallization starts before and progresses during the overheating. The surface...

The [3+2] cycloaddition between various nitriles and sodium azide proceeds smoothly in the presence of zeolite and sulfated Zircona as effective catalyst and in the water and DMF/MeOH, to give the corresponding arylaminotetrazoles in good to high yields. The reaction most probably precedes through the in situ formation of a catalyst azide species, followed by a successive [3+2] cycloaddition wi...

The [3+2] cycloaddition between various nitriles and sodium azide proceeds smoothly in the presence of zeolite and sulfated Zircona as effective catalyst and in the water and DMF/MeOH, to give the corresponding arylaminotetrazoles in good to high yields. The reaction most probably precedes through the in situ formation of a catalyst azide species, followed by a successive [3+2] cycloaddition wi...

Optimization studies for the esterification and transesterification of oil extracted from Croton gratissimus grains were carried out using response surface methodology (RMS) that utilizes central composite design (CCD) analysis variance (ANOVA). A 2 3 full-factorial rotatable CCD three independent variables at five levels was developed in each case, giving a total 20 experiments needed per stud...

nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...