Purity >98%. BMS-806 is a small molecule that inhibits the first step of HIV-1 infection by blocking the binding of host cell CD4 with viral gp120 protein. It binds the exterior envelope glycoprotein gp120 (Kd = 21.1 nM; Ki = 24.9 nM), blocking the conformational change that occurs with CD4 binding and preventing fusion of the viral and target cell membranes. BMS-806 is specific to HIV-1 irrespective of chemokine receptor preference, with no activity against HIV-2, SIV, or a panel of additional viruses.