公开(公告)号：DE59508621D1

公开(公告)日：2000-09-14

申请号：DE59508621

申请日：1995-09-23

Applicant: BASF AG

Inventor： KRAUSE DR ,  ERNST DR ,  PAUST DR ,  RHEUDE DR ,  DOBLER DR

IPC: C07C67/307 ,  C07C69/65 ,  C07F9/40

Abstract: Prodn. of trialkyl 4-phosphono-2-methyl-2-butenoate esters of formula (I) with a high E-isomer content comprises (a) reacting an alkyl 2-hydroxy-2-methyl-3-butenoate of formula (II) with PBr3 or PCl3 at 0-80 degrees C in the absence of pyridine to form a mixt. of an alkyl 4-halo-2- methyl-2-butenoate of formula (III) and an alkyl 2-halo-2-methyl-3-butenoate of formula (IV), and (b) reacting the mixt. with a trialkyl phosphite of formula (V) at 70-140 degrees C. R1, R2 = Me or Et; X = Cl or Br. Also claimed is the prodn. of (III) as in step (a) above at a temp. of 20-80 degrees C.