5-Pyrimidinecarboxylic acid, 4-(2-chloro-4-fluorophenyl)-2-(3,5-difluoro-2-pyridinyl)-6-[[4-[(1,1-dimethylethoxy)carbonyl]-1-piperazinyl]methyl]-1,4-dihydro-, methyl ester, (4R)- AIDS-180663 AIDS180663