FURAN DERIVATIVE

PURPOSE:To obtain new furan derivatives useful as medicines for diseases caused by a central nervous system disorders such as constipation, diarrhea, abdominal distention, Altzheimer geriatric dementia or amnesia. CONSTITUTION:A compound expressed by formula I [X is H, R7CH2-(R7 is lower alkoxy, etc.), etc.; R1 is H, lower alkyl, (substituted)phenyl, (substituted) aralkyl, picolyl, etc.; R2 to R6 are H or lower alkyl; (n) is 0 or 1], e.g. {1-[2-[(5- dimethylaminomethyl-2-furanyl) methylthio] ethyl]-2-imidazolidylidene} propanedinitrile. The compound expressed by formula I is e.g. produced by reacting a compound expressed by formula II with an equimolar compound expressed by formula III to afford a compound expressed by formula IV, reacting the compound of formula IV with a 1-3 equivalent sulfonyl halide to give a compound expressed by formula V (L is eliminable group such as sulfonates and then reacting the compound expressed by formula V with a compound expressed by formula VI [Xa is R8R9NCH2 (R8 and R9 are H, lower alkyl, etc.)] in a solvent in the presence of a base at ambient temperature for 2-7 day.