ISSN 1070-3632, Russian Journal of General Chemistry, 2008, Vol. 78, No. 11, pp. 2162–2163. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © A.I. Rakhimov, O.N. Kutyga, 2008, published in Zhurnal Obshchei Khimii, 2008, Vol. 78, No. 11, pp. 1926–1927.
LETTERS
TO THE EDITOR
Synthesis of α-tert-Butylperoxyethyl Perfluorocarboxylates
A. I. Rakhimov and O. N. Kutyga
Volgograd State Technical University
pr. Lenina 28, Volgograd, 400131 Russia
e-mail: organic@vstu.ru
Received May 15, 2008
DOI: 10.1134/S1070363208110339
α-Chloroalkyl-tert-butylperoxides react with alco-
hols to form tert-butylperoxy ethers, the initiators of
monomers polymerization and rubber vulcanization [1].
We synthesized some α-tert-butylperoxyethyl per-
fluoroalkylcarboxylates by reaction of α-chloroethyl-
tert-butylperoxide I with silver perfluorocarboxylates:
(CH3)3COOCH(CH3)Cl + RFC(O)OAg → (CH3)3COOCH(CH3)OC(O)RF,
II–VI
RF = CF3 (II), CF3(CF2)2 (III), СF3(CF2)3 (IV), CF3(CF2)5 (V), CF3OCF2CF2 (VI).
Reaction was carried out in hexane, Freon-113,
(7 mm Hg), d420 1.1703, nD20 1.3650. Found, %: C 41.98;
H 5.60; Oact 7.05; MRD 43.91. C8H13O4F3. Calculated,
%: С 41.73; Н 5.65; Оact 6.96; MRD 43.89.
chloroform, diethyl ether. The perfluorinated esters
yields were 44.5–65%. Better yields were obtained in
polar diethyl ether.
α-tert-Butylperoxyethyl perfluorobutyrate (III).
Yield 54.5%, bp 40–42°C (7 mm Hg), d420 1.3763, nD20
1.3561. Found, %: С 37.2; Н 3.85; Oact 4.81; MRD
56.69. C9H13O4F7. Calculated, %: С 36.36; Н 3.94; Oact
4.85; MRD 52.30.
Nucleophilic substitution of α-chloroperoxides and
α-chloroesters in polar media proceeds more readily
due to SN1 substitution mechanism. This mechanism is
proved by correlation of the first order rate constants
of hydrolysis in 87.65% dioxane and 12.35% water
with the positive charge ΣQ compensation in carbo-
cation of general formula ROCH2+ , where R = CH3,
OCH2Cl, OCH3 [2,3].
α-tert-Butylperoxyethyl perfluorovalerianate (IV).
Yield 57%, bp 36.5–37°C (1.5 mm Hg), d420 1.4560, nD20
1.3530. MRD 56.69, calculated 56.57. Found, %: С
33.7; Н 3.84; Oact 3.25. C11H13O4 F9. Calculated, %: С
34.66; Н 2.71; Oact 3.33.
α-tert-Butylperoxyethyl perfluoroacetate (II). To
a solution of 0.04 mol (8.8 g) of silver trifluoroacetate
(silver perfluorocarboxylate was prepared by the reac-
tion of the corresponding perfluorocarboxylic acids
with silver oxide [5]) in 60 ml of dry ether was added
0.04 mol (6.4 g) of the freshly distilled α-chloroethyl-
tert-butylperoxide at 0 to 5°C. Then temperature was
gradually increased. The reaction mixture was stirred
at 25–35°C for 3–4 h. Silver chloride precipitate was
filtered off. The organic mass was washed rapidly with
sodium hydrogen carbonate solution and water to
neutral reaction. After the solvent removal the residue
was distilled in a vacuum. Yield 65%, bp 27.5–28°C
α-tert-Butylperoxyethyl perfluoroheptanate (V).
Yield 57.8 %, bp 67.5–65.2°C (2 mm Hg), d420 1.5645,
nD20 1.3445. Found, %: С 33.00; Н 3.70; Oact 4.30; MRD
63.08. C13H13O4 F13. Calculated, %: С 32.5; Н 3.85;
Oact 4.39; MRD 62.93.
α-tert-Butylperoxyethyl perfluoromethoxybutyr-
ate (VI). Yield 44.5%, bp 40.5–41°C (13 mm Hg), d420
1.3744, nD20 1.3495. Found, %: С 34.64; Н 3.73; Oact
4.52; MRD 52.10. С10H13F7O5. Calculated, %: С 34.68;
Н 3.76; Оact 4.62; MRD 54.06.
2162
Rakhimov
