The proposed research is a comprehensive, 36 month, synthetic and biological testing program aimed at the development of novel non-steroidal male contraceptive agents that will adversely affect the progress of sperm maturation, as well as have a lethal effect on mature spermatozoa. It will prove that the proposed compounds will behave as specific inhibitors of LDH-C4, and in turn, will be effective and safe male contraceptive agents.