Novel hydroxamic acid derivatives, e.g., of formula (I), wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are as defined, are found to be useful as pharmaceuticals, e.g., for the suppression of TNF release and the treatment of autoimmune and inflammatory diseases, e.g., multiple sclerosis and rheumatoid arthritis. Methods of making the compounds, novel intermediates, and pharmaceutical compositions comprising the compounds are provided. ##STR00001##