Synthesis of phosphonoacetic acid esters and their practical application in the preparation of phosphorylated coumarins

摘要

Phosphonoacetic acid esters 1(R~1 = R~2 = Me,Et,i-Pr,R~3 = Et,i-Pr,PhCH2,ph)were obtained via Michaelis-Arbuzov reaction of alkyl phosphites with bromoacetates,carried out without solvent at 80-110℃.Treatment of 1 with salicylaldehyde in the presence of a catalyst(pyrrolidine and acetic acid)gave phosphorylated coumarins 2(R = Me,Et,i-Pr)with almost complete conversion and high isolated yields up to 75-85%.