L002 is a potent, cell permeable, reversible and specific acetyltransferase p300 (KAT3B) inhibitor with an?IC50?of 1.98 μM. L002 binds the acetyl-CoA pocket and competitively inhibits the FATp300 catalytic domain, blocks histone acetylation and p53 acetylation, and inhibits STAT3 activation. L002 has the potential for hypertension‐induced cardiac hypertrophy and fibrogenesis treatment.