| abstract |
Adipic acid (I) prodn. involves: (a) hydroformylation of pentenate esters (II) with CO and H2 at elevated temp. and pressure in the presence of Co or Rh carbonyl complexes (III), to give a mixt. (IV) of 5-, 4- and 3-formylvalerate esters; (b) sepn. of the 5-formylvalerate ester (V) from (IV), leaving a mixt. (VI) of 4- and 3-formylvalerate esters; (c) dehydrocarbonylation of (VI) in the presence of gp. VIII element(s) at 50-400 deg. C, to give (II), which are recycled to stage (a); (d) oxidn. of (V) with (gas contg.) O2, to give adipate monoesters (VII); and (e) hydrolysis of (VII) to (I). |