NEW MATERIAL: A compound of formula I [wherein A is formula II or formula III (wherein R1 and R2 are each H, a lower alkyl, or they may be combined with each other to form an alkylene; X is H, a lower alkyl, a halogen, OH, NO2, NH2, CF3 or the like; and p is 1 or 2); W is O, H2 or (H, OH); n is 2-4: and R3 is phenyl or the like] and an acid addition salt thereof.

EXAMPLE: 8-[3-[4-(1,2-Benzoylthiazol-3-yl)-1-piperazinyl]propyloxy]-8- azaspiro[4,5]decane-7,9-dione.

USE: An antipsychotic agent, an anxiolytic agent, an analgestic, etc.

PREPARATION: A compound of formula IV is reacted with a compound of formula V at 25-80°C under agitation in the presence of an acid scavenger (e.g. K2CO3) and a catalyst (e.g. NaI) in an inert gas atmosphere to obtain a compound of formula I.