Facile nitration of aromatic compounds using Bi(NO 3 ) 3 ·5H 2 O/MgSO 4 under mechanochemical conditions

Bi(NO 3 ) 3 ·5H 2 O/MgSO 4 was developed as an efficient and green reagent for the nitration of aromatic compounds under mechanochemistry (or ball milling) condition. While aromatics with weak activating groups such as phenyl could be nitrated by this reagent with 100% conversion, aromatics with weak deactivating groups such as chloro- or bromo- could also be nitrated but with moderate conversion and regioselectivity with big para / ortho ratios. The in situ generated N 2 O 4 or NO 2 due to the decomposition of Bi(NO 3 ) 3 ·5H 2 O promoted by MgSO 4 should be responsible for this mechanochemical nitration.