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 under conventional and ultrasonic sonication (US) and microwave (MW) conditions. Benzoylation is much more competent and faster than analogous VH ((Benzamide/ POCl3) or (Benzamide/SOCl2)) reagents and afforded benzoyl derivatives in fairly 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). Highly remarkable rate accelerations in MW assisted reactions are attributed to bulk activation of molecules, while US assisted reactions could be accounted for cavitation effects.