β-(3-Bromo-4-hydroxy-5-methoxyphenyl)alanine (RIT 1412), an antihypertensive agent

Abstract

β-(3-Bromo-4-hydroxy-5-methoxyphenyl)alanine (I) exerts a long-acting antihypertensive effect in rats and dogs. This unnatural amino-acid was synthesized by two different methods, i.e., via the azlactone (VI) and the corresponding phenylpyruvic acid (VIII), and also via the acetamidomalonic ester (V). Some derivatives of (I)[(IX)–(XII)], and the optical resolution of (I) into its enantiomers, are described. The results of the determination of the configuration of (–)-(I) and (+)-(I) by the enzymic path are in agreement with those obtained by the application of the Lutz–Jirgensons rule.