The present invention provides compounds of formula (I) ##STR00001## wherein R.sup.1 and R.sup.2 are as defined hereinabove.The compounds of the present invention are modulators, especially antagonists, of the activity of chemokine CCR5 receptors. Modulators of the CCR5 receptor may be useful in the treatment of various inflammatory diseases and conditions, and in the treatment of infection by HIV and genetically related retroviruses.