| abstract |
The present invention relates to a compound of the formula:n wherein R¹ stands for hydrogen or a lower alkyl; n denotes an integer of 1 to 6; X stands for an optionally oxidized sulphur atom, oxygen atom or an optionally substituted imino; R² stands for methyl or an organic residual group bonded through methylene, methine a quaternary carbon; R³ stands for a lower alkyl; R⁴ stands for hydrogen or acyl; R⁵ and R⁶ each stand for a lower alkoxy or a lower alkyl, or R⁵ and R⁶ combinedly stand for butadienylene, and salts thereof. n The compound (I) of the present invention has a strong 5-lipoxygenase inhibiting action, is of high safety and is useful as, among others, an agent for ameliorating circulatory system, an anti-allergic agent and a pharmaceutical agent for central nervous system. |