ultrasonic and microwave effects on the benzamide/sulfuryl chloride mediated benzoylation of benzene derivatives under vilsmeier-haack conditions

Benzamide/ sulfuryl chloride (so2cl2) reagent has been developed as a vilsmeier- haack(vh) reagent for benzoylation of aromatic compounds by using the conventional and ultrasonic sonication (us), and microwave (mw) conditions. benzoylation is much more competent and faster than the analogous vh ((benzamide/ pocl3) or (benzamide/ socl2)) reagents and afforded benzoyl derivatives in good yields.  reaction times are moderately less than those observed with [benzamide/ pocl3] and (benzamide/ socl2) reagents. reaction times are far less in microwave assisted (mwar) reactions than ultrasonically assisted (usas) reactions , which in turn are less than the conventional method with a decreasing  trend: mwar (seconds) << sonication (minutes) << conventional (hrs). the highly remarkable rate accelerations in mw assisted reactions are attributed to the bulk activation of the molecules; while us assisted reactions could be accounted for cavitation effects.