Abstract
Unlike the diformylation of the 2‐methyl group in 2‐methyl‐3‐aryl‐4(3H)quinazolone during the Vilsmeier reaction, the 2‐methyl group in 6‐nitro‐2‐methyl‐3‐aryl‐4(3H)quinazolones underwent monoformylation. An unprecedented attack of the iminium species generated in situ under the Vilsmeier conditions on the 3‐aryl ring of 6‐nitro‐2‐methyl‐3‐aryl‐4(3H)quinazolones provided a facile approach to the synthesis of tetracyclic 12‐ketoquino[2,1‐b]quinazolines.
Acknowledgment
H.S.B. is grateful to Colour Chem Limited, Thane, India, for financial support.