 This led to the discovery of etravirine which has a bromine substitution at the 5-position (R3) of the pyrimidine ring (with R1 = 2,6-dimethyl-4-cyanoanilino, R2 = NH2 and Y = O) (figure 5).Etravirine was discovered by researchers at the Jansen Research Foundation and Tibotec and approved in 2008 by the FDA.It is used in treatment-expirenced adult patients with HIV infection that is multidrug resistant in combination with other antiretroviral drugs.