The invention relates to substituted 3-phenyl-5-alkoxy-1,3,4-oxadiazol-2-ones, of general formula (I), wherein R1 represents C7-C22 alkyl, C2-C4 alkyl that is substituted by C4-C20 alkoxy, C6-C10 aryl, C6-C10 aryloxy or C4-C12-alkoxy-C2-C4-alkoxy, and represents C7-C20 alkenyl, 3 beta -cholestan-3-yl or substituted phenyl； R2, R3, R4 and R5 represent hydrogen, halogen, nitro, C1-C4 alkyl, C1-C9 alkyloxy, trifluoromethyl, trifluoromethoxy or C6-C10-aryl-C1-C4-alkyloxy, C6-C10 aryloxy, C6-C10 aryl, C3-C8 cycloalkyl or O-C3-C8-cycloalkyl, whereby all of these can be substituted. The invention also relates to methods for producing these compounds. The compounds of formula (I) have an inhibiting effect on the pancreatic lipase and can be used as active substances for treating obesity.
