5-HT3 RECEPTOR AGONIST, NOVEL THIAZOLE DERIVATIVE, AND INTERMEDIATE THEREFOR.

摘要

A 5-HT3 receptor agonist containing a thiazole derivative represented by general formula (I) as the active ingredient, a specified compound useful as a 5-HT3 receptor agonist, and a specified thioamide derivative useful as an intermediate therefor, wherein ring A represents one of the following rings which may be substituted by at least one substituent selected from the group consisting of halogen, lower alkyl and lower alkoxy: (1) a benzene ring, and (2) a 5- or 6-membered unsaturated heterocycle having one or two heteroatoms selected from among nitrogen, oxygen and sulfur; one of L1 and L2 represents a single bond, and the other of them is absent, or represents C1-C4 alkylene or C2-C5 alkenylene; R represents a group represented by any of general formulae: (1), (2), (3) and (4); L3 represents lower alkylene; L4 represents a single bond or lower alkylene; R1 and R2 represent each independently hydrogen, lower alkyl or an amino-protecting group; R3 represents hydrogen, lower alkyl, oxo or optionally protected amino; R4 is absent, or represents hydrogen, lower alkyl, aralkyl or an amino-protecting group; ring B represents one of the following rings which are either monocyclic or bicyclic and may bear an oxygen atom(s): (1) a nitrogenous saturated heterocycle bearing four to sixteen ring atoms, and (2) a nitrogenous heterocycle having a double bond and bearing four to sixteen ring atoms: and ring D represents a saturated carbocycle bearing four to eight ring atoms; provided the nitrogen atom of R may form an unsubstituted quaternary ammonium salt.