3-Chlorodiphenylamine is a high affinity燙a2+爏ensitizer爋f cardiac muscle. 3-Chlorodiphenylamine is based on diphenylamine and binds to the isolated N-domain of燾ardiac troponin C (cTnC)?(Kd=6 礛). 3-Chlorodiphenylamine is an excellent starting scaffold for the development of more potent Ca2+-sensitizing compounds due to its small size, and can be used for systolic heart failure research