Pharmaceutical compounds of the formula
in which R¹ and R³ are each C₁₋₄ alkyl or C₁₋₄ alkyl-carbonyl, and R² is carboxy, tetrazolyl, C₁₋₄ alkyl-sulphonamido or -CR⁴R⁵CO₂H where R⁴ and R⁵ are each hydrogen or C₁₋₄ alkyl; provided that when R¹ and R³ are both methyl and when R¹ and R³ are both methylcarbonyl, R² is not carboxy; and salts and esters thereof.
式中的药物化合物
其中 R¹ 和 R³ 各为 C₁₋₄ 烷基或 C₁₋₄ 烷基-羰基,R² 为羧基、
四唑基、C₁₋₄ 烷基-磺酰胺基或-CR⁴R⁵CO₂H,其中 R⁴ 和 R⁵ 各为氢或 C₁₋₄ 烷基;但当 R¹ 和 R³ 都是甲基和当 R¹ 和 R³ 都是甲基羰基时,R² 不是羧基;以及它们的盐和酯。