Back to results
US 5,292,973 AGranted
Phosphine oxide removal from compounds formed by a Wittig reaction
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsTakehiko Fukumoto, Akira Yamamoto
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsTakehiko Fukumoto, Akira Yamamoto
Estimating the term…
An improvement is proposed for the removal of the precipitates of a phosphine oxide compound as a by-product from a mixture thereof with an olefin compound obtained by the Wittig reaction for the preparation of the olefin compound from a phosphorane compound and a carbonyl compound. Instead of the conventional procedure of filtration to remove the precipitates, the mixture in a hydrocarbon solvent, after replacement of a non-hydrocarbon solvent with a hydrocarbon solvent, if necessary, is admixed with a lower carboxylic acid such as acetic acid so that the precipitates of the phosphine oxide are dissolved forming a viscous fluid which is immiscible with the mixture of the olefin compound and the hydrocarbon solvent. The fluid containing the dissolved phosphine oxide compound can be easily removed by phase separation so that a great increase is obtained in the yield of the desired olefin compound.
In a method for the removal of a phosphine oxide compound from a mixture of the phosphine oxide compound and an olefin compound formed by a Wittig reaction for the preparation of the olefin compound from a phosphorane compound and a carbonyl compound, the improvement which comprises the steps of:
In a method for the removal of precipitates of a phosphine oxide compound from a mixture of the phosphine oxide compound and an olefin compound in a non-hydrocarbon solvent formed by a Wittig reaction for the preparation of the olefin compound from a phosphorane compound and a carbonyl compound, the improvement which comprises the steps of:
Dependencies are inferred from the claim text.