Based on the notable effect of pyrimidines and chromenes in treating breast cancer [31,32,33,34,35,36,37,38,39,40] (Figure 4), their vital role in cell cycle arrest and apoptosis induction [41,42,43,44,45,46,47,48] and the previous finding about the structure features of Bcl-2 and Mcl-1 proteins/antagonist interaction, as well as the need for selecting less resistant drugs, our aim is to synthesize novel fused chromenopyrimidine with promising cell cycle arrest as well as dual Bcl-2 and Mcl-1 inhibitory activity through making some modifications in Bcl-2 and Mcl-1 candidates. This evidence concerns the gene MCL1 and breast cancer.