Spiro[2H-1-benzopyran-2,4'-piperidine]-4(3H)-one derivatives, acid addition salts thereof and pharmaceutical compositions containing them

PCT No. PCT/HU97/00012 Sec. 371 Date Feb. 12, 1998 Sec. 102(e) Date Feb. 12, 1998 PCT Filed Apr. 3, 1997 PCT Pub. No. WO97/37630 PCT Pub. Date Oct. 16, 1997The invention relates to novel spiro[2H-1-benzopyran-2,4'-piperidine]-4(3H)-one derivatives of formula (I), wherein R stands for halogen, nitro group or a straight or branched chain C1-6 alkyl group, and their acid addition salts, as well as their quaternary salts of formula (Ia) wherein R and R' are the same or different and are identical to the meaning of said (above) R or can mean also hydrogen; and Z represents one equivalent of an anion. The compounds of formulas (I) and (Ia) exert an improving effect on dementias of various pathological origin and accompanying symptoms thereof. Furthermore, the invention relates to a process for the preparation of compounds of formulas (I) and (Ia); to pharmaceutical compositions containing as active gents the above compounds of formulas (I) and (Ia); and to a method of treatment.