V.A. Petrov et al. / Journal of Fluorine Chemistry 125 (2004) 99–105
103
10 along with 4.8% of known C6F12 isomers, 9.6% of known
C8F16 isomers, and smaller amounts of higher boilers.
4.1.3. Synthesis of 2-trifluoromethyl-4,4,3,3,3-
pentafluoroethylbut-1-ene (2)
Fractionation afforded 66.5 g (50%) of 10, bp 106–
1
SOCl2 (30 g, 0.252 mol) was added dropwise to stirred
CF3CF(CH2OH)CFHCF3 [15] (30 g, 0.13 mol). The reac-
tion mixture was heated at 80À90 8C for 20 min. After
liberation of HCl was completed, the excess of SOCl2
was distilled off. The resulting mixture was added dropwise
to a suspension of dry KF (19 g, 0.39 mol) in N-methyl-
pyrrolidone (50 ml) with stirring at 25–30 8C. After the
completion of the exothermic reaction the agitation was
continued at 35 8C. After 2 h the product was distilled out
and redistilled at atmospheric pressure to give 23 g (83%) 2-
trifluoromethyl-4,4,3,3,3-pentafluoroethylbut-1-ene (2), bp
107.5 8C. H NMR (d, ppm): 6.6 (t, 16 Hz); 19F NMR (d,
ppm): À80.8 (3F, m), À82.4 (3F, m), À83.9 (3F, m), À108.9
(2F, m), À110.1 (2F, m), À111.2 (2F, m), À127.2 (2F, m); IR
(neat) (cmÀ1): 3105 þ 3034 (unsat. CH), 1674 (C¼C),
1250–1100 (CF).
4.1.2. Synthesis of Baylis–Hillman adducts 6–8 [8]
The procedure published in [8] was used for the prepara-
tion of compounds 6–8. Reactions of hexafluoroacetone and
1,3-dichlorotetrafluoroacetone with methyl acrylate were
carried out at ambient temperature, although better conver-
sions and yield of the product the reaction of tert-butyla-
crylate and hexafluoroacetone were achieved when it was
carried out at 80 8C (16 h).
39–40 8C; 1H NMR (d, ppm): 5.65 (1H, s), 5.85 (1H, s); 19
F
NMR (d, ppm): À64.9 (3F, m); À85.6 (3F, t, J ¼ 8 Hz);
À114.1 (2F, q, J ¼ 8 Hz), MS (m/z, intensity %): 195
[(M À Fþ), C5H2F7þ, 27.5], 145 (C4H2F5þ, 100); 119
(C2F5þ, 6.3) 95 (C3H2F3þ, 12.8), 69 (CF3þ, 11).
Compound 6: Reaction conditions: solvent THF, 80 8C,
16 h; yield of 6—58%, bp 32–34 at 0.27 mmHg; H NMR
1
(d, ppm): 2.2 (9H, s), 6.5 (1H, s), 7.0 (1H, s), 8.4 (1H, s); 19
F
4.1.4. Oxidation of olefins 1–10 by sodium hypochlorite or
sodium hypobromide under phase transfer catalysis
(d, ppm): À76.9 (s); IR (liquid, KBr; cmÀ1): 3144 (OH),
1730 (C¼O), 1618 (C¼C); GC/MS (m/e): 295 [M þ 1,
C10H13F6O3þ].
4.1.4.1. Method A: preparation of 1,1-bis(trifluoromethyl)-
ethylene oxide (1). Olefin 1 (25 ml, 40 g) was condensed in a
flask containing a solution of NaOCl (made at À5 to À3 8C
by bubbling 15 g of chlorine into a mixture of 50 ml of
50 wt.% of NaOH and 100 ml of water) and 0.5 g of phase
transfer catalyst—methyltricaprylylammonium chloride
(AliquatR-336)—was added at À2 to þ2 8C under vigo-
rous stirring. The reaction mixture was agitated at this
temperature till >95% conversion of olefin (GC) was
reached (ꢀ1–1.5 h). Crude reaction product was trans-
ferred out of the reactor under vacuum at 20–30 8C (250–
50 mmHg) in a cold trap (at À78 8C). The crude product was
dried over MgSO4 and distilled to give a 33 g (yield 75%) of
1a, bp 41–42 8C at 760 mmHg (reported), bp 41–42 8C
[5,20] and 39 8C [18].
Compound 7: Reaction conditions: solvent ether/THF
(1:1), 25 8C, 48 h; yield of 7—66%, bp 54 at 0.1 mmHg;
1H NMR (d, ppm): 3.8 (3H, s), 6.4 (1H, m), 6.8 (1H, m), 8.4
(1H, brs, OH); 19F (d, ppm): À62.0 (2F, dm, J ¼ 168 Hz),
À62.8 (2F, dm, J ¼ 168 Hz); IR (liquid, KBr; cmÀ1): 3213
(OH), 1695 (C¼O), 1616 (C¼C). Anal. Calc. for C7H6-
Cl2F4O3: C, 29.50; H, 2.12; F, 26.66. Found: C, 29.28; H,
2.15; F, 26.63.
Compound 8: Reaction conditions: solvent THF, 25 8C,
5 h, yield of 8—55%, bp 64–66 at 0.1 mmHg; 1H NMR (d,
ppm): 3.8 (3H, s), 3.9 (3H, s), 4.5 (1H, brs, OH), 6.2 (1H, m),
6.6 (1H, m); 19F (d, ppm): À74.7 (s); IR (liquid, KBr; cmÀ1):
3462 (OH), 1759, 1733 (C¼O), 1636 (C¼C); GC/MS (m/e):
243 [M þ 1, C8H10F3O5þ].
Table 1
Reactions conditions and ratio reagents for the oxidation of olefins 1–10
Olefin
(mol)
Methoda Catalystb
(mol)
Time
(h)
Temperature Product (s)
(8C)
Boiling point (8C/mmHg) Anal. found (calc.) or MS
(melting point)
(yield%)
1 (0.21)
2 (0.14)
3 (0.12)
4 (0.06)
5 (0.1)
A
A
A
C
A
B
B
B
B
B
D (0.002)
E (0.001)
1.5
5
2–5
1a (65–75)
2a (46)
3a (24)
4a (31)
5a (75)
6a (84)
7a (55)
8a (47)
9a (75)
10a (86)
42
C, 26.64 (26.68); H, 1.10 (1.12)
MS: 230 [Mþ, C5H2F8Oþ]c
25
2
59–60
E (0.002) 10–25
E (0.001) 10–25
E (0.002) 10–25
E (0.002) 10–25
E (0.002) 10–25
E (0.002) 10–25
E (0.002) 10–26
88.2–88.5
102.5
C, 26.44 (26.28); H, 1.31 (1.32); F, 50.03 (49.88)
3
C, 22.02 (22.00); H, 1.11 (1.06); F, 41.57 (41.76)
c
3
(56–58)
(80–82)
63–64/0.15
(67–69)
92/46
MS: 268 [Mþ, C7H6F6O4
]
þ
6 (0.05)
7 (0.09)
8 (0.06)
9 (0.08)
10 (0.05)
3
C, 38.94 (38.32); H, 4.05 (3.90); F, 37.01 (36.75)
C, 27.66 (27.93); H, 2.04 (2.01); F, 25.25 (25.25)
C, 37.03 (37.22); H, 3.64 (3.51); F, 21.91 (22.08)
4
4
d
]
MS: 213 [(M þ H)þ, C8H12F3O3
þ
2
E (0.002)
0–25 16
53.5–54.5/55
C, 24.03 (24.12); H, 0.22 (0.22)
a Method A—freshly prepared NaOCl; B—commercial NaOCl (Aldrich, 10–12% of available chlorine); C—freshly prepared sodium hypobromite.
b Catalyst D—Aliquat 336R; E—(C4H9)4NHSO4.
c GC/MS, electronic ionization.
d GC/MS, chemical ionization.