(S)-6-chloro-4-(Cyclopropylethynyl)-1,4-dihydro-(S)-6-chloro-4-(cyclopropylethynyl)-1,4-dihydro-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one
efavirenz, (S)-isomer