反应详情

The key step of the synthesis of (S)-4,5-dihydro-2-(2-hydroxy-3-methoxyphenyl)-4-thiazolecarboxylic acid (6) was cyclocondensation of D-cysteine with 2-hydroxy-3-methoxybenzonitrile. The cyano intermediate was obtained from o-vanillin by treatment with nitroethane in sodium acetate and acetic acid. (S)-4,5-Dihydro-2-(2-hydroxy-4-carboxyphenyl)-4-thiazolecarboxylic acid (7) was synthesized by a similar reaction sequence. 4-Formyl-3-hydroxybenzoic acid was converted to 4-cyano-3-hydroxybenzoic acid using nitroethane in sodium acetate and acetic acid; cyclization with D-cysteine completed the synthesis of dicarboxylic acid chelator 7.