methacrolein

In this scientific contribution, regio- and diastereo- selectivity of [3+2] cycloaddition (32CA) of N-tert-butyl,α-(4-trifluoromethyl)-phenylnitrone (1) with methacrolein (2) were investigated using DFT method at B3LYP/6-31(d) computational level in gas and dichloromethane solvent. The molecular electrostatic potential MESP was used to show the most active centers in the examined molecules. Global and local reactivity indices as well as thermodynamic parameters have been calculated to explain the regioselectivity and stereoselectivity for the selected reaction.

The joint process of isobutylene oxidation and butene-1 oxidative dehydration is studied on the basis of Fe-Te-Mo-Ox catalyst in the impulse flown plant. The optimal process conditions of products yield (methacrolein, butadiene-1,3) are determined. It is shown that the selectivity by butadiene-1,3 increases with the contact time rising at 633 K and the selectivity by methacrolein at 693 K is maximal at contact time of 0.6 s. The maximal total yield of the target reaction products (68.7 %) is obtained at 693 K and contact time of 3.6 s.

Oxidation of tert-butyl alcohol (TBA) to methacrolein (МA) over Fe-Te-Mo-Ox catalyst (Cat), promoted by Ca(NO3)2 has been investigated. Promoter concentration, which was optimal by the МA yield, has been established (Ca/Mo = 0.05). Using catalyst of such type the MA yield was 87.1 % (calculated for supplied TBA) at the temperature of 663 K, process time of 2.5 s and TBA concentration of 7.0 % with concentration of water vapour in the air of 20 %. Under mentioned conditions TBA conversion was 100 %, isobutylene conversion – 95.5 %, selectivity by MA was 87.6 % and by CO2 – 2.4 %.