EP0637586A1 — 2-(Piperidin-4-yl, pyridin-4-yl and tetrahydropyridin-4-yl)benzofuran-7-ol and carbamate derivatives, their preparation and their use as acetylcholinesterase inhibitors

USPTO Abstract

2-(piperidin-4-yl, pyridin-4-yl and tetrahydropyridin-4-yl)benzofuran-7-ol and carbamate derivatives of the formula I wherein R₁ is hydrogen, loweralkyl, arylloweralkyl, CONHR₅ or CONR₆R₇ R₂ is hydrogen, cyano, CH₂NR₈R₉, CONHR₅ or CONR₆R₇; R₃ is where R₁₀ is hydrogen, loweralkyl, arylloweralkyl, CONHR₅, CONR₆R₇, acyl, acyloxyloweralkyl or acyloxyarylloweralkyl; R₄ is hydrogen, halogen, loweralkyl or loweralkoxy; R₅ is hydrogen, loweralkyl or arylloweralkyl; R₆ is loweralkyl or arylloweralkyl; R₇ is loweralkyl or arylloweralkyl; R₈ is hydrogen, loweralkyl, arylloweralkyl or acyl; R₉ is hydrogen, loweralkyl or arylloweralkyl; R₁₁ is loweralkyl, aryl or arylloweralkyl; with the proviso that if R₁ is hydrogen or loweralkyl, R₂ cannot be hydrogen; or a pharmaceutically acceptable acid addition salt thereof, or where applicable, an optical or geometric isomer or racemic mixture thereof, which are useful as acetylcholinesterase inhibitors and as such may be useful for the treatment of Alzheimer's disease and other senile dementias.