the present invention provides benzamide inhibitors of the p2x 7 receptor of the formula : wherein r 1 - r 3 are as defined herein . the compounds of the invention are useful in the treatment of il - 1 mediated disorders , including , without limitation , inflammatory diseases such as osteoarthritis and rheumatoid arthritis ; allergies , asthma , copd , cancer , reperfusion or ischemia in stroke or heart attack , autoimmune diseases and other disorders .