| abstract |
Compounds of formula (I):(wherein: R<sup>1</sup> represents an optionally substituted alkyl, cycloalkyl, aryl, partially hydrogenated aryl or heterocyclic group; R<sup>2</sup>, R<sup>3</sup>, R<sup>4</sup> and R<sup>5</sup> represent hydrogen or an optionally substituted alkyl, cycloalkyl, aralkyl, aryl, heterocyclic or heterocyclic-alkyl group or any adjacent pair thereof form a cyclic structure, at least one not being hydrogen; A represents a bond, or a methylene, ethylene, oxymethyl or thiomethyl group; B represents an alkylene, alkylidene, cycloalkylene or cycloalkylidene group; and n is 0, 1 or 2) and salts and esters thereof are hypotensive agents. |