5-HT3 RECEPTOR AGONIST, NOVEL THIAZOLE DERIVATIVE AND INTERMEDIATE THEREOF

摘要

A 5-HT3 receptor agonist containing a thiazole derivative represented by general formula (I) as the effective ingredient; a specified compound useful as a 5-HT3 receptor aganist; and a specified thioamide derivative useful as an intermediate therefor. <IMG> (I) wherein each symbol represents the following meaning: Ring A: the following ring which may be substituted by one or more substituents selected from the group consisting of a halogen atom, a lower alkyl group and a lower alkoxyl group: 1) a benzene ring, or 2) a 5-membered or 6-membered unsaturated heterocyclic ring having one or two hetero atoms selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom, L1 and L2: one of them represents a single bond, and the other one represents non-existence, or an alkylene group having 1 to 4 carbon atoms or an alkenylene group having 2 to 5 carbon atoms, R: a group represented by one of the following formulae: <IMG> , <IMG> , <IMG> or <IMG> L3: a lower alkylene group, L4: a single bond or a lower alkylene group, R1 and R2: the same or different and individually a hydrogen atom, a lower alkyl group or an amino-protecting group, R3: a hydrogen atom, a lower alkyl group, an oxo group or a protected or unprotected amino group, R4: non-existence or a hydrogen atom, a lower alkyl group, an aralkyl group or an amino-protecting group, Ring B: the following monocyclic or bicyclic ring which may contain an oxygen atom: 1) a nitrogen-containing saturated heterocyclic ring having 4 to 16 ring-forming atoms, or 2) a nitrogen-containing heterocyclic ring having one unsaturated bond and 4 to 16 ring-forming atoms, and Ring D: a saturated carbon ring having 4 to 8 ringforming atoms, with the proviso that a nitrogen atom in the group R can become a quaternary ammonium salt accompanied by a substituent.