Exfluor News





Perfluorodecalin, Perfluorooctane, and PFOB Increased Production Capacity

Exfluor Research Corporation is pleased to announce increased production capacity of Perfluorodecalin (CAS# 306-94-5), Perfluorooctane (CAS# 307-34-6), and Perfluorooctyl Bromide (CAS# 423-55-2). Metric ton quantities are available. Exfluor supplies perfluorocarbons to all industries and can assist medical researchers with acquiring cGMP quality material through our sister company, FluoroMed L.P. FluoroMed specializes in manufacturing high purity perfluorocarbons for medical applications. Please contact our sales team at 512-310-9044 or email at info@exfluor.com for more information.


ACS Regional Meeting Sponsorship and Dr. Richard J. Lagow Symposium

Exfluor Research Corporation is proud to be a sponsor of the 2011 Southwest Regional American Chemical Society Meeting in Austin, TX from November 9-12, 2011 where a symposium honoring the life and works of Dr. Richard J. Lagow was featured. During his professional career, Dr. Lagow received numerous awards and recognitions, including the ACS award for Creative Work in Fluorine Chemistry. Dr. Lagow will be missed but his legacy in the field of fluorochemicals will continue.


Dr. Richard J. Lagow

Dr. Richard J. (Dick) Lagow, PhD, was carried home by his angels on Monday, April 26, 2010, after a long battle with Alzheimer's Disease, with his beloved wife Roxann Parker-Lagow at his side. Dr. Lagow was born on August 16, 1945, in Albuquerque, NM to parents Faye and Ruthe Lagow.

He graduated in 1963 with honors from Bryan Adams High School in Dallas, TX. He received a football and chemistry scholarship to Rice University where he was a three year letterman and went on to graduate with his B.A. in 1967 and earned his PhD in 1969. In 1970, Dr. Lagow earned a N.S.F. Postdoctoral Fellowship, and received the I.R. 100 Award. From 1974-75, Dr. Lagow was an Alfred P. Sloan Fellow. In 1992, he was bestowed the Alexander von Humboldt Award while being honored as a Fellow, American Association for the Advancement of Science. In 1997, Dr. Lagow was bestowed the great honor of the American Chemical Society Award for Creative Work in Fluorine Chemistry.

Dr. Lagow was an instructor in the Department of Chemistry at Rice University, Houston, from 1967-69; Assistant Professor, Associate Professor, Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 1969-76; Associate Professor, Department of Chemistry, The University of Texas at Austin, 1976-80; Professor, Department of Chemistry, The University of Texas at Austin, 1980-1994; and L.N. Vauquelin Regents Professor of Chemistry, Department of Chemistry, The University of Texas at Austin, September 1994 - onward. Dr. Lagow honorably received tenure from UT-Austin.

Dr. Richard J. Lagow, founded and served as President of Exfluor Research Corporation in Austin, TX. He authored 212 chemical publications and was responsible for 81 U.S. Patents in various fields of chemistry. Richard was exceptionally passionate about travel for both business and pleasure, served as visiting professor and lectured at universities around the world, all along with his wife at his side.

Dr. Lagow is preceded in death by his loving parents, Faye and Ruthe Lagow and brother, Bill Lagow. He is survived by the love of his life, his wife Roxann Parker-Lagow. He is also survived by daughters Micale Crawford (husband Neal), Kristen Bettis (husband Craig) and son Robert D. Lagow (wife Carrie); Grandchildren MeKenna, Caelan, and William Crawford, soon to be born, granddaughter Skylee Lagow and the mother of his children, Bobbie D. Lagow. He also leaves behind his beloved mother-in-law, Lucille Parker and numerous nieces and nephews.

A special gratitude to Dr. Lagow's extraordinary caregivers Maria Herrera, Candice Nichols and for the loving care by Maria Chagoya and her family and all the staff members of Grady Woods II Nursing Home. Dr. Lagow was a caring son, a loving husband, a dedicated and loving father, a brilliant professor and a loyal friend. He will be deeply missed by all whose lives he touched.

Memorial donations may be made to the Alzheimer's Association, 3429 Executive Center Drive - #100, Austin, TX, 78701.


Synthesis of Unique Fluorinated Diols

The following is a report written by Dr. Hajimu Kawa, Dr. Thomas R. Bierschenk, Dr. Timothy J. Juhlke, and Dr. Richard J. Lagow.  The report was presented by Dr. Kawa  at the Fluorine in Coatings III meeting in Orlando, Florida, January 25-27, 1999.

Introduction

Most fluoropolymers currently available are made from fluoroolefins. Many research chemists, who are involved in the development of new fluoropolymers, are aware that commercially available fluorinated monomers other than fluoroolefins are difficult to find. Fluorinated versions of common polymers, such as polyurethanes, polyesters, polyamides and acrylic polymers, are not commercially available simply because of the lack of fluorinated monomers.


Exfluor Research Corporation has been engaged in the development of highly fluorinated functional monomers since more than a decade ago. Our technology is based on direct fluorination in which elemental fluorine is used to replace hydrogen atoms in organic compounds with fluorine atoms. For example, n-nonane is converted to perfluoro-n-nonane by direct fluorination.


Since there are unlimited source of hydrocarbons, direct fluorination enables one to synthesize many new fluorinated compounds. One of our most significant achievements was the development of a process that made it possible to synthesize a wide variety of perfluoroesters. For example, pentyl pentanoate can be converted to the corresponding perfluoroester ( I ).



One mole of the perfluoroester ( I ) can be hydrolyzed to give two moles of perfluoropentanoic acid.




Similarly, one mole of ( I ) can be reacted with methanol to give two moles of methyl perfluoro-pentanoate.




Perfluoropentanoic acid can be treated with F2/Br2 to give Perfluoropentyl bromide1).




Methyl perfluoropentanoate can be reduced to give perfluoropentyl methanol.




Table-1 shows our products that are currently available in commercial quantities.




Synthesis of new diols

We have successfully synthesized various diols as shown above. Those diols have linear structures in that difluoromethylene groups are sandwiched by two hydroxymethyl groups. Inserting more or less difluoromethylene groups can control the total fluorine content.




In this paper, we wish to report our recent development of the synthesis of new fluorinated diols having branching perfluoroalkyl groups. Branching perfluoroalkyl groups extending out from polymer backbone would work as a protective layer to keep the polymer from severe environments. Using larger or smaller perfluoroalkyl groups can control the total fluorine content.



Method

Branched perfluoroalkyl groups, such as secondary and tertiary perfluoroalkyl moieties, sometimes act as pseudo halogens and therefore are good leaving groups. Because of this, it is very difficult to synthesize perfluoroalkyl methanols, Rf-CH2OH, that have branching at the carbon atom next to the CH2OH group (this carbon atom can be referred to as the a -carbon atom). For example, it was observed that methyl perfluoro-2-hexyl decanoate which has branching at the a -carbon atom did not yield the corresponding perfluoroalkyl methanol when the ester was reduced under standard conditions for the reduction of linear perfluoroesters, such as by treatment of the ester with lithium aluminum hydride or sodium borohydride. The products of attempted conventional reduction reaction were quite complicated. It is believed that when there is a branch site at the carbon atom next to the carbonyl group, the secondary perfluoroalkyl group becomes a better leaving group than the alkoxy group because of the two strong electron withdrawing perfluoroalkyl groups. Thus, the secondary perfluoroalkyl group becomes a leaving group upon attack by hydride ion on the carboxylic ester functionality, producing a perfluoroalkyl anion and a formate ester, as shown in Scheme 1.




The perfluoroalkyl anion can rapidly decompose into an olefin (Scheme 2), which can react with the reducing reagent or with solvent to give a complicated product mixture.







On the other hand, when perfluoro (2-hexyldecyl acetate) was reduced with sodium borohydride, the corresponding branched perfluoroalkyl methanol, perfluoro-1H,1H-2-hexyldecanol, was obtained in an excellent yield.

A suggested reaction mechanism is shown in Scheme 3. After the initial attack of hydride ion, a perfluoroalkoxide anion forms. The anion rearranges into a perfluoroacyl fluoride and fluoride ion. When hydride anion attacks the perfluoroacyl fluoride, fluoride ion, instead of the secondary perfluoroalkyl group, leaves the molecule because fluoride ion is a better leaving group than the secondary perfluoroalkyl group. Thus, an a-branched perfluoroalkyl methanol was produced successfully by reduction of a perfluoroester

It was found that the reduction of perfluoroesters generally gave no complicated products but the expected perfluoroalkyl methanols in good to excellent yield under simple conditions. Since perfluoroalkoxy groups are generally better leaving groups than perfluoroalkyl groups, the reduction reaction proceeded smoothly to yield perfluoroalkyl methanols or perfluoroalkylene dimethanols even when there was a branch site at the carbon atom next to the carbonyl group.

An exemplary reaction scheme for the reduction of a perfluoroalkyl ester of a perfluoroalkyl carboxylic acid is shown in scheme 4.




Without wishing to be bound by theory, it is believed that initial hydride attack at the carbonyl group of (i) (in which Rf and Rf’ are both perfluoroalkyl moieties, which can be the same or different) initially yields a perfluoroalkanal (aldehyde) (ii) and a perfluoroalkoxide ion (iii). The perfluoroalkanal (ii) is further reduced to the perfluoroalkyl methanol (iv). Perfluoroalkoxide ion (iii), on the other hand, immediately decomposes into perfluorocarboxylic acid fluoride (v) and fluoride ion. Since the fluoride group is a very good leaving group, as mentioned earlier, the perfluorocarboxylic acid fluoride (v) can be reduced {via perfluoroaldehyde (vi)} to another perfluoroalkyl methanol (vii) even if the group Rf’ is a secondary or tertiary perfluoroalkyl group.


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Synthesis of 1,3-propanediols

1,3-Propanediols having branching perfluoroalkyl groups were synthesized from alkyl-substituted diethyl malonates. An alkyl-substituted diethyl malonate was fluorinated to give the corresponding perfluoroester ( II ). The perfluoroester ( II ) was then directly reduced with sodium borohydride to give 2-fluoro-2-perfluoroalkyl-1,3-propanediol.




1,3-Propanediols having short chain, long chain or branched chain perfluoroalkyl groups were synthesized.



Synthesis of 1,4-butanediols

Perfluoroalkyl-substituted 1,4-butanediols were synthesized from commercially available gamma lactones. For example, undecanoic g-lactone was fluorinated to give the corresponding perfluorolactone ( III ). Reduction of ( III ) gave perfluoro-1H,1H,4H-undecane-1,4-diol.




Synthesis of 1,5-pentanediols

Perfluoroalkyl-substituted 1,5-pentanediols were synthesized most conveniently from commercially available delta lactones. For example, dodecanoic d-lactone was fluorinated to give the corresponding perfluorolactone ( IV ). Reduction of ( IV ) with sodium borohydride gave perfluoro-1H,1H,5H-dodecane-1,5-diol.




Summary

A wide variety of new perfluorodiesters having branching perfluoroalkyl groups were synthesized by direct fluorination. It was found that the reduction of those perfluorodiesters proceeded smoothly to give the corresponding diols in good yields even when there was a branch site at the carbon next to the carbonyl group. The unique branching structure is expected to provide a protective layer to keep polymer backbone from severe environments.


Acknowledgement

This work was partially funded by the U.S. Air Force.


References

1) "Method of Producing Perfluorocarbon Halides" U.S. Patent No. 5,455,373.