THIOPHENE COMPOUND

PROBLEM TO BE SOLVED: To obtain a new compound having a selective affinity for especially Y5 receptor among neuropeptide Y receptors and useful for feeding control and for prophylactics and/or treatments of diabetes, hypercholesterolemia, hyperlipemia, etc. SOLUTION: This compound is a compound of formula I (R1 to R4 are each H or a lower alkyl and R1 and R2, and R3 and R4 can respectively form rings by binding to each other; and X is oxygen or sulfur). The compound of formula I is obtained, for instance, by reacting a compound of formula II (e.g. 3- hydroxy-2-thiophenecarboxyaldehyde) with a compound of formula III (e.g. Dimedon) followed by reacting the resultant product with a compound of formula IV. It is preferable to use about 1.5-3 mol of each compound of formulas III and IV per mol of the compound of formula II in the above reactions. The reaction temperature and time of the above reactions are preferably 50-150 deg.C and 1-6 h.