Single pot process for synthesis of side chain for taxol useful as cancer chemotherapeutic, involves reacting formed bromoacetate with sodium nitride followed by diacetylation, and benzoylating and hydrogenating resulting azido alcohol

摘要

(2R,3S)-2,3-dihydroxy-3-phenylpropionate is converted into bromoacetate without further crystallization. The bromoacetate is reacted with sodium nitride in an organic solvent followed by diacetylation with sodium acetate in another organic solvent to obtain azido alcohol. The azido alcohol is subjected to benzoylation followed by hydrogenation to obtain (2R,3S)-(N-)-benzoyl-3-phenylisoserine methyl ester. (2R,3S)-2,3-dihydroxy-3-phenylpropionate is synthesized by tandem or simultaneous Heck coupling of bromobenzene and methylacrylate and N-oxidation of amine in the presence of cinchona alkaloid and using a recyclable multifunctional catalyst. The obtained diol is converted into bromoacetate without further crystallization. The bromoacetate is reacted with sodium nitride (NaN 3) in an organic solvent followed by diacetylation with sodium acetate (NaOAc) in another organic solvent to obtain an azido alcohol. The azido alcohol is subjected to benzoylation followed by hydrogenation to obtain (2R, 3S)-(N-)-benzoyl-3-phenylisoserine methyl ester. The multifunction catalyst is of formula IE-IE-PdOsW (I), where IE is ion exchanger selected from LDH, quaternary ammonium salt anchored on silica, clay, alumina, magnesia and resin.