Novel asymmetric thioethers of the formula ##STR1## in which the general symbols have the following meanings: a is an integer of from 1 to 7, R.sup.o represents hydrogen or C.sub.1-7 -alkanoyl, R.sup.1 represents C.sub.1-3 -alkyl which may be substituted at the terminal carbon atom by a free or acylated hydroxy group, by a halogen atom having an atomic number of at most 17, or by methoxy, or represents C.sub.1-3 -perfluoroalkyl, R.sup.2 represents an optionally unsaturated aliphatic radical having from 5 to 15 carbon atoms, A represents ethylene or alternatively, if R.sup.1 represents a halogenated radical and/or B represents phenylene or ethylene, a single bond or vinylene, B represents a single bond, ethynylene or phenylene, R.sup.3 represents hydroxy, C.sub.1-7 -alkoxy or an optionally substituted amino group, and --X-- represents a single bond, a methylene group of an optionally N-acylated primary aminomethylene group, and their salts are active as leucotriene antagonists since they eliminate the contractions of smooth muscles brought about by leucotrienes, and are therefore suitable for the treatment of allergic, especially asthmatic, conditions.
式子为##STR1##的新型不对称
硫醚化合物,其中一般符号具有以下含义:a是1至7的整数,R.sup.o表示氢或C.sub.1-7-烷酰基,R.sup.1表示C.sub.1-3-烷基,该烷基可以在末端碳原子上被自由或酰化羟基,具有最多17个原子序数的卤素原子,或甲氧基取代;或表示C.sub.1-3-
全氟烷基,R.sup.2表示具有5至15个碳原子的可选不饱和脂肪基,A表示
乙烯或者,如果R.sup.1表示卤代基和/或B表示苯基或
乙烯,则表示单键或
乙烯基,B表示单键,
乙炔基或苯基,R.sup.3表示羟基,C.sub.1-7-烷氧基或可选取代的
氨基基团,--X--表示单键,一个可选的N-酰化的一级
氨基甲基基团的亚甲基基团,它们的盐对
白三烯受体具有拮抗作用,因为它们消除了
白三烯引起的平滑肌收缩,因此适用于过敏性疾病,特别是哮喘的治疗。