Patent ID: 6444096
Filing Date: 2002-09-03
Classification: C07C

Abstract:
Process for the recovery of cyclobutanone in a purity of at least 90 weight percent from a crude product mixture comprising cyclobutanone, water and a plurality of other organic compounds resulting from the oxidation of cyclobutanol in water by the steps comprising:(1) distilling the crude product mixture to obtain (i) a distillate comprising cyclobutanone, water, and the plurality of other organic compounds comprising cyclopropanemethanol, cyclobutanol, 3-butene-1-ol, 2-butene-1-ol, cyclopropanecarboxaldehyde, ethers and mixed ethers of cyclobutanol, cyclopropanemethanol, 3-butene-1-ol, and 2-butene-1-ol, and hemi-ketals and ketals of cyclopropanemethanol, cyclobutanol, 3-butene-1-ol and 2-butene-1-ol with cyclobutanone; and (ii) a distillation residue comprising water, metal salts, and high boiling organic compounds; (2) allowing the distillate from step (1) to separate into (i) an organic phase comprising a minor amount of the cyclobutanone contained in the distillate and a major amount of impurities less soluble in water than cyclobutanone; and (ii) an aqueous phase comprising water, a major amount of the cyclobutanone contained in the distillate, and a minor amount of more hydrophilic impurities; (3) distilling the aqueous phase from step (2) to obtain (i) a minor amount of distillate comprising low-boiling azeotropes comprising water and organic impurities in the aqueous phase, (ii) a major amount of distillate comprising an azeotrope of water and cyclobutanone, and (iii) a distillation residue comprising water, cyclopropanecarboxylic acid, &ggr;-butyrolactone, cyclobutanol, cyclopropanemethanol, mixed ethers of cyclobutanol, cyclopropanemethanol, 3-butene-1-ol, and 2-butene-1-ol, and ketals formed from reactions between cyclopropanemethanol, cyclobutanol, 3-butene-1-ol and 2-butene-1-ol and cyclobutanone; (4) allowing distillate (ii) from step (3) to separate into (i) a cyclobutanone-rich organic phase comprising cyclobutanone, water, and a plurality of close-boiling aldehydes comprising cyclopropanecarboxaldehyde and cis/trans crotonaldehydes and (ii) an aqueous phase comprising cyclobutanone and water; and (5) distilling the organic phase (i) from step (4) to obtain (i) a first distillate comprising an azeotrope of water and cyclobutanone, (ii) a second distillate comprising cyclobutanone having a puritiy of at least 90%, and (iii) a distillation residue comprising cyclobutanol, cyclopropanemethanol, mixed ethers of cyclobutanol, cyclopropanemethanol, 3-butene-1-ol, and 2-butene-1-ol, and ketals formed from reactions between cyclopropanemethanol, cyclobutanol, 3-butene-1-ol and 2-butene-1-ol and cyclobutanone.