METHOD FOR PREPARING 2-ETHYLHEXANOIC ACID Russian patent published in 2005 - IPC

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for preparing 2-ethylhexanoic acid. Method involves catalytic hydrogenation of fraction isolating from the manufacturing waste in the presence of hydrogen by rectification method followed by oxidation of prepared hydrogenation product with air oxygen at temperature 30-80°C and under pressure 0.1-1.0 MPa. Vat residue from rectification of butyl alcohols in oxo-synthesis is used as raw for the process. Fraction with the total content of unsaturated and saturated C₈-alcohols 65-95 wt.-% is isolated from vat residue by rectification and in residual pressure on column top 100-300 mm of mercury column. This fraction is subjected for hydrogenation in vapor phase under atmosphere pressure, temperature 220-270°C, volume rate of raw feeding 0.5 h^-1, volume ratio raw : hydrogen = 1:1 on copper-containing catalyst and the following isolation 2-ethylhexanal from catalyzate by rectification on two columns working at residual pressure on top of the first column 60-100 mm of mercury column and on top of the second column 20-80 mm of mercury column, and 2-ethylhexanal is oxidized with air oxygen. The end 2-ethylhexanoic acid is isolated from the prepared oxidized product by rectification on two columns working at residual pressure on top of column 20-70 and 10-60 mm of mercury column, respectively. Method provides enhancing the yield of 2-ethylhexanoic acid.

EFFECT: improved method for preparing.

2 cl, 16 ex