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V. F. DeTURI ET AL.
9-YPhFl-9-d. To incorporate tritium into the 9-position,
0.5 g of 9-YPhFl and six drops of HOT was dissolved in
4 mL anhydrous glyme. The addition of 1 mL of 0.3 M
MeONa/MeOH gave a precipitate that dissolved on
heating the solution at 508–608C for 20 min at which time
2–3 mL conc. HCl was added. The 9-YPhFl-9-t crystal-
lized on cooling to room temperature. All compounds
were recrystallized from ethanol.
summers in Leiden was received from grants by the
Faculty of Mathematics and Natural Sciences of Leiden
University and the Ithaca College Dana Internship Pro-
gram.
REFERENCES
1. Ritchie CD. J. Am. Chem. Soc. 1969; 91: 6749.
2. Streitwieser AJr, Scannon PJ, Neimeyer NM. J. Am. Chem. Soc.
1972; 94: 7938.
3. Streitwieser AJr, Hudson JA, Mares F. J. Am. Chem. Soc. 1968; 90:
648–651.
Synthesis of YC6H4CiHClCF3
A three-step synthesis started with YC6H4MgBr and
CF3CO2H to make the corresponding ketone.35 The
p-NO2C6H4COCF3 was synthesized from the reaction of
methyl p-nitrobenzoate with (trifluoromethyl)trimethyl-
silane with anhydrous tetrabutylammonium fluoride [in
THF] as the initiator and toluene as the solvent.36,37
Ketones were reduced with the appropriate sodium
borohydride to give the isotopically labeled alcohols,
which were then converted to the chloride by a reaction
with triphenylphosphine and carbon tetrachloride.14
Yields for the formation of the ketones are normally
between 50% and 70%, except for p-NO2C6H4COCF3
which was obtained in only 30%–50% yield. Although
the yields for the last two steps were variable depending
on the student, they can be carried out in 90% yield.
4. Streitwieser AJr, Hollyhead WB, Pudjaatmake AH, Owens PH,
Kruger TL, Rubenstein PA, MacQuarrie RA, Brokaw ML, Chu
WKC, Niemeyer HM. J. Am. Chem. Soc. 1971; 93: 5088–5096.
5. Cram DJ, Scott DA, Nielsen WD. J. Am. Chem. Soc. 1961; 83:
3696.
6. Koch HF, Biffinger JC, Mishima M, Mustanir, Lodder G. J. Phys.
Org. Chem. 1998; 11: 614–617.
7. Swain CG, Stivers EC, Reuwer RT, Schaad LJ. J. Am. Chem. Soc.
1958; 80: 5885–5893.
8. Streitwieser AJr, Hollyhead WB, Sonnichsen G, Pudjaatmake AH,
Chang CJ, Kruger TL. J. Am. Chem. Soc. 1971; 93: 5096–5102.
9. Reference 4 has the values of kD/kT from 2.54 ꢃ 0.11 to 2.46 ꢃ 0.20
and kH/kT from 16.1 ꢃ 0.6 to 15.9 ꢃ 0.6. Our values come from rate
constants obtained from our Arrhenius plots for all three isotopes
of 9-PhFl-9-iH, see Table I.
10. The original Swain–Schaad relationship7 (kH/kT) ¼ (kH/kD)1.442
becomes (kH/kT) ¼ (kD/kT)3.26. For hydron exchange reactions
the later relationship is more useful. The Streitwieser group8 uses
3.344 as the exponent in their treatment. We use 3.344 value for our
calculations.
11. The equation for aT is given in reference 8 p. 5099. We thank Prof.
Andrew Streiwieser for supplying the equations to calculate aH and
aD.
Synthesis of YC6H4CiH(CF3)2
12. Albery WJ, Knowles JRJ. Am. Chem. Soc. 1977; 99: 637–638.
13. Koch HF, Dahlberg DJJ. Am. Chem. Soc. 1980; 102: 6102–6107.
14. Koch HF, Lodder G, Koch JG, Bogdan DJ, Brown GH, Carlson
CA, Dean AB, Hage R, Han P, Hopman JCP, James LA, Knape
PM, Roos EC, Sardina ML, Sawyer RA, Scott BO, Testa CAIII,
Wickham SD. J. Am. Chem. Soc. 1997; 119: 9965–9974.
15. Since kD/kT values are near unity for the ring substituted com-
pounds of C6H5CiH(CF3)2 and C6H5CiHClCF3, rates for the
deuterium and tritium derivatives are used interchangeably.
16. (a) Fujio M, Miyamoto T, Tauji Y, Tsuno Y. Tetrahedron Lett.
1991; 32: 2929–2932. (b) Fujio M, Nakashima K, Tokunaga E,
Tauji Y, Tsuno Y. Tetrahedron Lett. 1991; 33: 345–348.
17. Streitwieser AJr, Koch HF. J. Am. Chem. Soc. 1964; 86: 404–409.
18. Koch HF, Dahlberg DB, Lodder G, Root KS, Touchette NA, Solsky
RL, Zuck RM, Wagner LJ, Koch NH, Kuzemko MA. J. Am. Chem.
Soc. 1983; 105: 2394–2398.
—
The synthesis of C H C(CF ) CF has been described
—
in the literature, and the same method was used to make
6
5
3
2
35
the other YC H C(CF ) CF compounds. The reac-
—
—
—
6
4
3
2
tion of YC H C(CF ) CF with a threefold excess of
—
6
4
3
2
CsF in dimethylformamide resulted in the formation of
YC6H4CH(CF3)2, which was isolated by a co-distillation
with water. The compound was pure enough to use in the
kinetics experiments. Better than 99% incorporation of
deuterium to form YC6H4CD(CF3)2 was realized when
the reaction mixture was spiked with a tenfold excess of
D2O. The synthesis of C6H5CT(CF3)2 used an equal
molar amount of HOT.
19. Koch HF, Pomerantz WC, Ruggles EL, van Laren M, van Roon
A-M. Collect. Czech. Chem. Commun. 2002; 67: 1505–1516.
20. Koch HF, Koch JG, Koch NH, Koch AS. J. Am. Chem. Soc. 1983;
105: 2388–2393.
21. A detailed discussion of this can be found in reference 14,
pp. 9970–9971.
22. Koch HF. Acc. Che. Res. 1984; 17: 137–144.
23. Koch HF, Mishima M, Zuilhof H. Ber. Bunsenges. Phys. Che.
1998; 102: 567–572.
Acknowledgements
V.F.D. gratefully acknowledges the Camille and Henry
Dreyfus Foundation for a grant to support this research.
H.F.K. thanks both the Camille and Henry Dreyfus
Foundation and the donors of the Petroleum Research
Fund, administered by the American Chemical Society,
for support. M.M. gratefully acknowledges support by a
Grant-in-Aid for Scientific Research from the Ministry of
Education, Culture, Sports, Science and Technology,
Japan. Support for the Ithaca College students working
24. Ervin KM, DeTuri VF. J. Phys. Chem. A 2002; 9947–9956.
25. Miller WT, Fager EW, Griswold PH. J. Am. Chem. Soc. 1948; 70:
431–432.
26. (a) Hine J, Wiesboeck R, Ghirardelli RG. J. Am. Chem. Soc. 1961;
83: 1219–1222. (b) Hine J, Wiesboeck R, Ramsay OB. J. Am.
Chem. Soc. 1961; 83: 1222–1226.
27. Koch HF, Kielbania AJJr. J. Am. Chem. Soc. 1970; 92: 729–730.
28. Koch HF, Koch JG, Donovan DB, Toczko AG, Kielbania AJJr. J.
Am. Chem. Soc. 1981; 103: 5417–5423.
29. At 708C the rate correction for alkoxide-promoted dehydrofluor-
inations MeOH [1.0] vs. EtOH [30].
Copyright # 2006 John Wiley & Sons, Ltd.
J. Phys. Org. Chem. 2006; 19: 308–317
DeTuri, Vincent F.
