| abstract |
The present invention provides a compound of formula (I):n or a pharmaceutically acceptable salt thereof, wherein one of R¹, R², R³ and R⁴ represents a hydrocarbon or hydrocarbyloxycarbonyl group and the remaining groups R¹, R², R³ and R⁴ independently represent hydrogen, hydrocarbon, hydrocarbyloxycarbonyl, halogen, hydroxy or C₁₋₆ alkoxy, or R¹ and R² or R³ and R⁴ may together represent the residue of a carbocyclic ring; R⁵ and R⁶ independently represent hydrogen, hydrocarbon, hydroxy or fluoro; R⁷ represents hydrogen or C₁₋₃ alkyl; and R⁸ represents methyl or ethyl; which compounds are useful as anticonvulsant agents and in the treatment of neurodegenerative diseases. |