Quinazolin-4-one 1 was identified as an inhibitor of the HIF-1α transcriptional factor from a high-throughput screen. HIF-1α up-regulation is common in many cancer cells. In this Letter, we describe an efficient one-pot sequential reaction for the synthesis of quinazolin-4-one 1 analogues. The structure–activity relationship (SAR) study led to the 5-fold more potent analogue, 16.