| abstract |
According to the invention there is provided a compound the formula I; wherein : A is an optionally substituted: phenyl, naphthyl, pyridyl, pyrazinyl, pyridazinyl, paramidal, thienyl, thiazolyl, oxazolyl or thiadiazolyl; B is an optionally substituted: phenyl, pyridyl, thiazolyl, oxazolyl, thienyl, thiadiazolyl, isoxazole, pyrazole, furyl, pyrrolyl, imidazolyl, pyrazinyl, pyridazinyl, pyrimidyl, pyridone, pyrimidone, pyrazinone or pyridazinone; X is optionally substituted: pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, pyrrolyl, thienyl, furyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl or phenyl. R1 is CO2H, CO2R, COSO2NR2, tetrazolyl, P(O) or (OR)2 or SONH2. R2 is H, C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl or C1-3 alkylaryl. R3 is H or C1-5 alkyl. R4 is H or C1-5 alkyl. |