Patent ID: 6030505
Filing Date: 2000-02-29
Classification: C07C

Abstract:
A process for separating 5-formylvaleric esters in a yield of not less than 90% by distillation of a mixture, obtained from the output of a process for the hydroformylation of 4-pentenoic ester or a mixture of 3-and/or 4-pentenoic esters, comprising(a) a formylvaleric ester mixture,(b) the pentenoic ester(s) used,(c) valeric ester,(d) high boilers and(e) low boilersby distilling off the(1) low boilers, the pentenoic ester(s) used and valeric ester via the top in a first distillation column (1), low boiler column, at a pressure in the range from 10 to 300 mbar and bottom temperatures in the range of not greater than 150.degree. C.,(2) feeding the remaining bottoms from (1) to a second distillation column(2), isomer column, and separating off 3 and/or 4-formylvaleric esters via the top at a pressure in the range from 2 to 100 mbar and bottom temperatures in the range of not greater than 150.degree. C. and(3) feeding the remaining bottoms from (2) to a third distillation column (3) and separating 5-formylvaleric ester via the top at a pressure in the range from 1 to 20 mbar and bottom temperatures in the range of not greater than 150.degree. C. wherein the process steps are carried out at 0<t<5 h.