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1
are in Hz. Raman spectra were obtained using solid samples
and 782 nm laser excitation.
C3F7–CO–NH–C4F9: NMR (CD3CN): H: d 9.6 (NH).
17O: d 389. 19F: d À80.3 (t, 9, C3F7 CF3), À80.6 (tt, 10, 3,
C4F9 CF3), À93.9 (t, 13, NH–CF2), À119.7 (q, 9, CF2CO),
À123.0 (m, C4F9 CF3CF2CF2), À125.8 (m, C4F9 CF2CF3),
À126.4 (s, C3F7 CF2CF3).
Perfluoro-5-aza-4-nonene was prepared by a modification
of methodology reported by Petrov et al. [13] which involves
cracking of perfluoro(tributylamine) and elimination of
C4F10 in a reaction catalyzed by strong Lewis acids. The
procedure reported here uses a small flask as a continuous
reactor, allowing a relatively large quantity of substrate to be
processed with minimum use of catalyst. It emphasizes
efficiency over yield.
(C3F7CO)2NH: NMR (CD3CN): 1H: d 10.7 (NH). 17O: d
435. 19F: d À80.1 (t, 9, CF3), À118.9 (q, 9, CF2CO) and
À125.7 (s, CF2CF3).
3.2. Ammonolysis of C3F7–CF¼N–C4F9
Fluoroimine 1 was prepared by dropwise addition under
nitrogen of 90 g (C4F9)3N (3M) to stirred SbF5, 36 g, con-
tained in a 100 ml flask and heated to ca. 120–140 8C with an
oil bath. The rate of addition was adjusted so as to provide
brisk evolution of the product, which was removed as it
formed by distillation through a short-path distillation head;
72 g was collected. An alembic is useful for this purpose for it
minimizes contact between 1 and hot SbF5. This is advanta-
geous because these two compounds can react further with
eliminationofC4F10 andformationofC3F7CN.Thecombined
distillates from several such reactions, 603 g, were washed
twice with 150 ml ice water then dried over CaCl2 to give
450 g crude product. Distillation through a 16 in. spinning
band column gave 206 g (44%) of 1, bp 99–102 8C. The
compound was handled in a well-ventilated hood.
Liquid ammonia, 5 ml, was condensed upon 2.65 g 1 at
À1768. The reaction mixture was warmed to À788.
Unreacted ammonia and 1 were pumped away. The residue
was fractionated on a high vacuum line by distillation
through a series of U-traps. A liquid, which passed slowly
through a À788 trap, was collected. On standing at 308, it
slowly crystallized to give clear, colorless blades of 5, 0.4 g
(31%). Anal. Calcd. for C4H3F7N2: C, 22.6; H, 1.4; N, 13.2.
Found: C, 22.4; H, 1.4; N, 13.1. Mass spectrum: m/z 212.1076
(Mþ, Calcd. 212.1079); self-CI MS: m/z 213 ðMþ þ HÞ.
1
NMR (CD3CN): H: d 5.3 (w/2 106 Hz); 19F: d À80.3 (t,
9, CF3), À120.2 (q, 9, CF2CN), À126.8 (s, CF2CF3).
The X-ray powder pattern of the non-volatile residue,
1.2 g, demonstrated that it was [NH4]F along with about 5%
[NH4][HF2].
Imide 4 was prepared from C3F7CONH2 and excess
1
(C3F7CO)2O [3]. Distillation gave a product that, by H
and 17O NMR analysis, contained 80% 4 and 20% unreacted
2. This, and other moisture sensitive compounds, were
handled (and Nujol mulls for IR spectra prepared) under
nitrogen in a drybox.
3.3. Reaction of C3F7–CF¼N–C4F9 with hydrazine
Hydrazine (97%, anhydrous, 0.78 g, 24 mmol) was sus-
pended with stirring in 30 ml anhydrous diethyl ether and
cooled to 4 8C. Fluoroimine 1, 2.16 g (4.9 mmol), was added
dropwise. After warming to room temperature, the ether
phase was filtered off, washed with water and dried over
MgSO4. The residue remaining after evaporation of the ether
was sublimed under vacuum and the sublimate recrystallized
from carbon tetrachloride to give 0.55 g (28%) 6 as tiny,
colorless needles, mp 106–106.5 8C (sealed capillary). Anal.
Calcd. for C8HF14N3: C, 23.7; H, 0.2; N, 10.4. Found: C,
24.0; H, 0.3; N, 10.5. Electron impact mass spectrum: m/z
386 ðMþ À FÞ, 286 ðMþ À C2F5Þ. Negative ion FAB MS: m/
3.1. Hydrolysis of C3F7–CF¼N–C4F9
(A) Water (0.166 g, 9.2 mmol) was added slowly by
microliter syringe to a stirred solution of 2.0 g
(4.6 mmol) 1 in 30 ml dry ether. After 16 h, the solution
was transferred to a sublimer and the ether was removed
under high vacuum. The sublimer probe was cooled to
À78 8C and heating to 458 then led to collection of 1.0 g
of white, waxy sublimate. This was extracted with
20 ml Freon 113 (CF2Cl–CFCl2). Infrared analysis
showed that the insoluble material, 0.65 g, was mostly
C3F7CONH2; and that the soluble material (0.35 g)
contained (C3F7CO)2NH along with smaller amounts of
C3F7–CO–NH–C4F9 and C3F7CO2H.
(B) A solution of 1.89 g (4.4 mmol) 1 in 15 ml ether was
treated with 0.073 g H217O (20 at.% 17O, 4.1 mmol).
After 30 min, volatiles were removed on the vacuum
line. Analysis by infrared and 1H and 17O NMR
spectroscopy of the residue, 1.1 g, revealed a 79:19:2
mixture of 3, 4 and 2.
1
z 404 ðMþ À HÞ. NMR (CD3CN): H: d 10.8 (NH). 13C: d
151.5 (t, 2JCF ¼ 30, CN), 118.6 (qt, 287, 34, CF3), 111.6 (tt,
256, 31, CF2CN), 109.4 (th, 266, 37, CF2CF3). 19F: d À80.1
(t, 9, CF3), À112.5 (q, 8, CF2CN), À126.6 (s, CF2CF3). IR
(thin film): 3127, 3051, 2988, 2926, 2844, 2778, 2712, 2641,
2564, 2474, 1453, 1346, 1218, 1123, 1036, 893, 886. 743,
669, 607 and 543 cmÀ1. IR (CD3CN): 3142, 3074, 2993,
2937, 2906, 2828, 2800, 2775, 2714, 2636 and 2561 cmÀ1
.
Raman: 1551, 1499, 1353, 1323, 1328, 1039, 895, 783, 733,
676, 624, 381, 352 and 305 cmÀ1. Ultraviolet spectrum
(CH3CN): lmax 207 nm (log e 2.88).
The N-deuterated analog was prepared by dissolving 6 in
CH3OD under nitrogen and then removing the methanol
under vacuum. IR (Nujol): 2458, 2381, 2305, 2264, and
C3F7CONH2: NMR (CD3CN): 1H: d 7.3, 6.9 (NH2). 17O:
d 330. 19F: d À80.6 (t, 9, CF3), À120.0 (q, 9 CF2CO),
À126.8 (s, CF2CF3).
2172 cmÀ1
.