This invention relates to methods of treating an HIV infection with novel heterocyclic compounds of formula I wherein R.sup.1--R.sup.4, X.sup.1 and X.sup.2 are as defined in the summary and pharmaceutically acceptable salts, and methods to inhibit or modulate Human Immunodeficiency Virus (HIV) reverse transcriptase with compounds of formula I. ##STR00001##
CROSS REFERENCE TO PRIOR APPLICATION
This application is a divisional application of U.S. Ser. No. 10/807,766 filed Mar. 23, 2004 now U.S. Pat. 7,208,509 under Title 35 U.S.C. 121, which claims benefit of U.S. Provisional Application No. 60/457,130, filed Mar. 24, 2003, which is hereby incorporated by reference in its entirety. The related application, now U.S. Ser. No. 10/807,993, filed Mar. 23, 2004 entitled Non-Nucleoside Reverse Transcriptase Inhibitors (J. P. Dunn et al.), is hereby incorporated by reference in its entirety.
