| PATENT ASSIGNEE'S COUNTRY | USA |
| UPDATE | 04.00 |
| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 04.04.00 |
| PATENT TITLE |
Triphenylbis (fluoroalkoxy) phosphoranes and fluorinated ketals |
| PATENT ABSTRACT |
Novel triphenylbis(fluoroalkoxy)phosphoranes and a process for their preparation are disclosed. Also disclosed is a process for making fluorinated ketals by reacting phosphoranes with fluorinated ketones. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | 07.10.94 |
| PATENT REFERENCES CITED |
Lowthere, N. et al, J. chem. Soc., Chem. Comm., 1303 91985). Von Itzstein, M. et al, Aust, J. Chem., 36, 557 (1983). Denney, D.B. et al, J. Am. Chem. Soc., 103, 1785 (1981). Kubota, T. et al, J. Org. Chem., 45, 5052 (1980). Shermalovich, Yu. G. et al, Zh. Org. Khim, 52, 2526 (1982). Kubota, T. et al, Chemistry Letters, pp. 845-846. |
| PATENT PARENT CASE TEXT | This data is not available for free |
| PATENT CLAIMS |
What is claimed is: 1. A ketal of the formula: ##STR4## wherein R.sub.f is selected from straight chain or branched perfluoroalkyl, perfluoroalkenyl, perfluoroalkynyl, perfluoroalkoxy, perfluoroalkenoxy, perfluorochoroalkyl, perfluorochloroalkenyl, perfluorochloroalkynyl, perfluorochloroalkoxy, and perfluorochloroalkenoxy of 1-20 carbon atoms, and R.sub.f ' is a straight chain or branched perfluoroalkyl group, a perfluoroalkenyl group, a perfluoroalkynyl group, a perfluoroalkoxy group, a perfluoroalkenoxy group, a fluoroalkyl group, a fluoroalkenyl group, a fluoroalkynyl group, a fluoroalkoxy group, or a fluoroalkenoxy group of 1 to 20 carbon atoms. 2. The ketal compound as described by claim 1 wherein R.sub.f is selected from CF.sub.2 Cl, CF.sub.2 CF.sub.3, CFClCF.sub.2 Cl, and CF.sub.2 =CFOCF.sub.2 CF(CF.sub.3)OCF.sub.2 CF.sub.2. 3. The ketal compound, as described in claim 1, wherein R.sub.f ' is a C.sub.1 to C.sub.20 perfluoroalkyl |
| PATENT DESCRIPTION |
FIELD OF THE INVENTION Novel triphenylbis(fluoroalkoxy)phosphoranes are disclosed. Also disclosed are fluorinated ketals made from these phosphoranes with fluorinated ketones and a process for their preparation. TECHNICAL BACKGROUND One triphenylbis(fluoroalkoxy)phosphorane, Ph.sub.3 P(OCH.sub.2 CF.sub.3).sub.2, has been disclosed in the literature. See the following references a-d: a) N. Lowther and C. D. Hall, J. Chem. Soc., Chem. Comm., 1303 (1985) describe the preparation of Ar.sub.3 P(OCH.sub.2 CF.sub.3).sub.2 (Ar=substituted phenyl rings) by the reaction of Ar.sub.n P(OR).sub.n-3 (n=0 to 3) with PhSOCH.sub.2 CF.sub.3 and the mechanisms in the hydrolysis of these phosphoranes. b) M. Von Itzstein and I. D. Jenkins, Aust, J. Chem., 36, 557 (1983), disclose a method for the preparation of dialkoxytriphenylphosphoranes by the reaction of Ph.sub.3 P with alcohols in the presence of azodicarboxylates and the mechanism for this reaction. This paper deals mainly with hydrocarbon phosphoranes and only one fluorinated compound Ph.sub.3 P(OCH.sub.2 CF.sub.3)2 was described. The fluorinated compound is prepared either by their new method or reaction of Ph.sub.3 PBr.sub.2 and CF.sub.3 CH.sub.2 OH in the presence of Et.sub.3 N. The later reaction is the same as that used herein. c) D. B. Denney et al., J. Am. Chem. Soc., 103, 1785 (1981) report the preparation of phosphoranes containing the trifluoroethoxy group and the reaction of these fluorinated phosphoranes with alkoxides such as trifluoroethoxide. d) T. Kubota et al., J. Org. Chem., 45, 5052 (1980) used bis (2,2,2-trifluoroethoxy)triphenyl- phosphorane as a condensation reagent for alcohols with thiols. The preparation of Ph.sub.3 P(OCH.sub.2 CF.sub.3).sub.2 and application of this reagent in organic synthesis is described in detail. These researchers prepared Ph.sub.3 P(OCH.sub.2 CF.sub.3).sub.2 from the reaction of Ph.sub.3 PBr.sub.2 and NaOCH.sub.2 CF.sub.3 and investigated the reactions of Ph.sub.3 P(OCH.sub.2 CF.sub.3)2 with alcohols, carboxylic acid, thiols and amines. This reference also mentions the reaction of Ph.sub.3 P(OCH.sub.2 CF.sub.3).sub.2 with hydrocarbon aldehydes to give the corresponding acetals. e) Yu. G. Shermalovich et al., Zh. Org. Khim, 52, 2526 (1982) report that (CF.sub.3).sub.2 C(OCH.sub.2 CF.sub.2 CF.sub.2 H).sub.2 has been prepared from the reaction of hexafluoroacetone (HFA) and P(OCH.sub.2 CF.sub.2 CF.sub.2 H).sub.5 The reaction of P(OCH.sub.2 Rf).sub.5 (Rf=((CF.sub.2)nH, n=2,4) with carbonyl compounds is reported. Although the one mentioned fluorinated ketal, (CF.sub.3).sub.2 C(CH.sub.2 CF.sub.2 CF.sub.2 H).sub.2, was prepared by reaction of P(OCH.sub.2 CF.sub.2 CF.sub.2 H).sub.5 with hexafluoroacetone, the starting material used was different from that used herein; applicant's starting material is Ph.sub.3 P(OCH.sub.2 Rf).sub.2. Applicant believes that the method reported could not be adapted to prepare (CF.sub.3).sub.2 (OCH.sub.2 CF.sub.3).sub.2 by the reaction of HFA with P(OCH.sub.2 CF.sub.3).sub.5. SUMMARY OF THE INVENTION Novel triarylbis(fluoroalkoxy)phosphoranes, 1, Ar.sub.3 P(OCH.sub.2 Rf).sub.2 1 are disclosed. In formula 1, Ar is phenyl (hereinafter Ph) or Ph substituted with alkyl or other substituents that are selected so as not to interfere with the process reaction. R.sub.f is a perfluoroalkyl group, a perfluoroalkenyl group or a perfluoroalkynyl group of 1 to 20 carbon atoms, optionally substituted by one or more chlorine or hydrogen atoms, and optionally containing one or more oxygen atoms. The perfluoroalkyl group, perfluoroalkenyl group or perfluoroalkynyl group may be straight chain or branched, provided, however, that R.sub.f is not CF.sub.3. Preferred R.sub.f groups are selected from the group consisting of CF.sub.2 Cl, CF.sub.2 CF.sub.3, CFClCF.sub.2 Cl, and CF.sub.2 =CFOCF.sub.2 CF(CF.sub.3)OCF.sub.2 CF.sub.2. Also disclosed is a process for making fluorinated ketals of the formula 2 from phosphoranes of formula 1 by reaction of these phosphoranes with fluorinated ketones. ##STR1## In formula 2: R.sub.f is a perfluoroalkyl group, a perfluoroalkenyl group or a perfluoroalkynyl group of 1 to 20 carbon atoms, optionally substituted by one or more chlorine atoms, and optionally containing one or more oxygen atoms. The perfluoroalkyl group, perfluoroalkenyl group or perfluoroalkynyl group may be straight chain or branched. Preferred R.sub.f groups are selected from the group consisting of CF.sub.2 Cl, CF.sub.2 CF.sub.3, CFClCF.sub.2 Cl, and CF.sub.2 =CFOCF.sub.2 CF(CF.sub.3)OCF.sub.2 CF.sub.2. R.sub.f ' is a straight chain or branched perfluoroalkyl group, a perfluoroalkenyl group or a perfluoroalkynyl group of 1 to 20 carbon atoms, optionally substituted by one or more hydrogen atoms and optionally containing one or more oxygen atoms. Preferred R.sub.f ' groups are C.sub.1 to C.sub.20 perfluoroalkyl. Especially preferred are CF.sub.3 and CF.sub.2 CF.sub.3. The process for the preparation of various triphenylbis(fluoroalkoxy)phosphoranes involves the reaction of triphenylphosphine dibromide and the corresponding fluoroalcohols in the presence of a tertiary amine. The triphenylbis(fluoroalkoxy)phosphorane product of this reaction can then be used to prepare fluorinated ketals when reacted with the corresponding ketones, as shown below. ##STR2## wherein R.sub.f and R.sub.f ' are as defined above. The process can be conducted neat or in the presence of a solvent for one or both of the reagents, within a temperature range of about 20.degree. C. to about 250.degree. C. DETAILED DESCRIPTION OF THE INVENTION Although a number of triphenylbis(alkoxy)-phosphoranes, Ph.sub.3 P(OCH.sub.2 R).sub.2, have been reported in the literature, the preparation of only one triphenylbis-(fluoroalkoxy)phosphorane, Ph.sub.3 P(OCH.sub.2 CF.sub.3).sub.2, is known. The preparation of this fluorinated phosphorane was achieved by the reaction of Ph.sub.3 P with either CF.sub.3 CH.sub.2 OH, in the presence of diethyl azodicarboxylate, or trifluoroethyl benzenesulfonate. Ph.sub.3 P(OCH.sub.2 CF.sub.3).sub.2 can also be prepared by reaction of Ph.sub.3 PBr.sub.2 and NaOCH.sub.2 CF.sub.3. References for these various methods are listed in the Technical Background on page 1, herein. An efficient process for the preparation of various triphenylbis(fluoroalkoxy)phosphoranes involves reaction of triphenylphosphine dibromide and the corresponding fluoroalcohols in the presence of a tertiary amine (e.g., triethylamine), as shown by the example, below, where R.sub.f is a perfluoroalkyl group, a perfluoroalkenyl group or a perfluoroalkynyl group of 1 to 20 carbon atoms, optionally substituted by one or more chlorine or hydrogen atoms, and optionally containing one or more oxygen atoms. The perfluoroalkyl group, perfluoroalkenyl group or perfluoroalkynyl group may be straight chain or branched. Preferred R.sub.f groups are selected from the group consisting of CF.sub.2 Cl, CF.sub.2 CF.sub.3, CFClCF.sub.2 Cl, and CF.sub.2 =CFOCF.sub.2 CF(CF.sub.3)OCF.sub.2 CF.sub.2. ##STR3## Ph.sub.3 P(OCH.sub.2 Rf).sub.2 can then be reacted with the corresponding ketones to produce fluorinated ketals. There appear to be no universal methods for the preparation of fluorinated ketals of the formula (R.sub.f ').sub.2 C(OCH.sub.2 Rf).sub.2. As indicated in the Technical Background, above, one fluorinated ketal, (CF.sub.3).sub.2 C(OCH.sub.2 CF.sub.2 CF.sub.2 H).sub.2, has been reported, which was prepared from the reaction of hexafluoroacetone (HFA) and P(OCH.sub.2 CF.sub.2 CF.sub.2 H).sub.5. However, that reported method for making (CF.sub.3).sub.2 C(OCH.sub.2 CF.sub.2 CF.sub.2 H).sub.2 was found not to extend to prepare (CF.sub.3).sub.2 C(OCH.sub.2 CF.sub.3).sub.2 by the reaction of HFA with P(OCH.sub.2 CF.sub.3).sub.5. The present process can be carried out neat (no solvent) or in the presence of aprotic solvents such as, but not limited to, dichloromethane, 1,1,2-trifluoro-trichloroethane, ether, acetonitrile, dimethylformamide (DMF), benzene, toluene and chlorobenzene. The process is carried on at temperatures from ambient (about 20.degree. C.) to about 250.degree. C. A preferred temperature range is about 100.degree. C. to about 200.degree. C. It is most preferred to conduct the process at about 150.degree. C. to about 200.degree. C. There are no specific pressure requirements. Autogeneous pressure is sufficient. The fluorinated ketals produced are useful synthetic intermediates for fluorocarbon compounds and as monomers for fluoropolymers. |
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| PATENT PHOTOCOPY | Available on request |
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