Compounds 1 - ((adamantyl) alkyl) -3 - ((pyridinyl) alkyl) urea TNFalpha inhibitors useful for autoimmune diseases.

A purpose of the present invention is to provide TNF- alpha production inhibitors being useful as therapeutic agents for autoimmune diseases such as rheumatoid arthritis. Novel compounds having the structure represented by the general formula A1U or salts thereof according to the present invention have excellent TNF- alpha production inhibitory activities, wherein "A" is -(NR )-, -(CR R )- or -O-, "B" is alkylene or alkenylene, R , R , R , R and R are hydrogen, alkyl, alkenyl or the like, R is aryl or unsaturated heterocycle, R is hydrogen or alkyl, "X" is O or S, and "n" is an integer of 1 to 5.