NEW MATERIAL:The compound of formula I {A is R2-N< [R2 is (substituted) lower alkyl, lower alkenyl, lower alkynyl or adamantyl] or group of formula II; m and n are 0W2; X is O or S; R1 is H, (substituted) lower alkyl, lower alkenyl, lower alkynyl, (halogen-substituted) phenyl or adamantyl} or its salt.
EXAMPLE: 3-Ethyl-8-methyl-1-oxa-3,8-diazaspiro[4,5]decane-2,4-dione.
USE: Remedy for diseases caused by the degeneration of central nervous system such as Alzheimer's disease, Alzheimer-type senile dementia Huntington's chorea, Pick's disease, tardive dyskinesia, etc.
PREPARATION: A hydroxy-substituted heterocyclic carboxylic acid ester of formula III [A1 is R4-N<; R3 is ester residue; R4 is (substituted) lower alkyl, etc.] is made to react with urea or thiourea of formula IV.
TSUKAMOTO SHINICHI
ICHIHARA MASATO
USUDA SHINJI
HARADA MASATOMI
