In order to mitigate the lone pair repulsion and meanwhile maintain the carbonyl π bond property, we replaced the cyclopropanecarbonyl group with six-or fivemembered heterocycles (Table ). The activity of 2-pyridyl compound 7b received a markable improvement since the probability of the repulsion was cut by half (the repulsion take place only when the pyridine N atom turn towards the quinazoline core).