The present invention relates to novel to P2X.sub.7 inhibitors of formula I ##STR00001## and to processes for their preparation, intermediates useful in their preparation, pharmaceutical compositions containing them, and their use in therapy. The active compounds of the present invention are potent inhibitors of P2X.sub.7 and as such are useful in the treatment of inflammation, osteoarthritis, rheumatoid arthritis, cancer, reperfusion or ischemia in stroke or heart attack, autoimmune diseases and other disorders.