114
K.-W. Chi et al. / Journal of Fluorine Chemistry 103 (2000) 105±115
(2F, F11), 43.3 (2F, F14), 37.5 (2F, F12), 36.6 (2F, F15), 88.7
[M±CF3] (18), 266 [M±CF3±F] (2), 235 [M±C2F5]
(100), 216 [M±C2F6] (7), 188 [M±CF4±C5H4N] (1),
(1F, F2); 13C NMR ((CD3)2CO) dF: 159.1 (C4,
2JC 25.7 Hz), 150.5 (C6), 148.2 (C10), 139.0 (C7),
16
119 [C2F5] (1), 100 [CF2=CF2] (1), 78 [C5H4N] (26),
F
121.7 (C9), 116.3 (C8), 117.6 (C13, 1JC 287.2 Hz,
69 [CF3] (6); HRMS(CI) Calc. 354.0215 for C11H4F10N2;
F
1
2
2JC 33.8 Hz), 117.5 (C , JC 287.2 Hz, JC
14
Found: 354.0221. 2-Penta¯uoroethyl-3-tri¯uoro-methyl-
pyrido[1,2-a]pyrimidin-4-one (26) (2.2 g, 20%); Mp 100±
1018C (sublimed readily at 1408C/0.4 Torr); IR 910, 1050
(C±O), 1240±1120 (C±F), 1320, 1340 (C±N), 1490, 1520
(C=CAr), 1635 (C=N), 1690 (C=C), 1700 as (C=O), 1720 s
(C=O), 3120 (C±H) cm 1; lmax (EtOH)/nm 244 (e 1710),
370 (e 3890); 1H NMR (CD3)2SO) d: 9.20 (H10, d,
J 6.4 Hz), 8.28 (H8, t, J 6.4 Hz), 7.90 (H7, d,
J 6.4 Hz), 7.67 (H9, t, J 6.4 Hz); 19F NMR (CD3)2SO)
dF: 106.2 (3F, F11, t, JF±F 21.8 Hz), 83.9 (3F, F13, s), 53.9
(2F, F12, q, JF±F 21.8); 13C NMR ((CD3)2SO) dF: 154.6
F
F
F
33.8 Hz), 108.6 (C11, 1JC 266.0 Hz, 2JC 31.0 Hz),
F
F
1
2
2
108.5 (C , JC 266.2 Hz, JC 31.1 Hz, JC
F
F
F
4 Hz), 108.5 (C12, 1JC 265.9 Hz, 2JC 38.3 Hz),
F
F
108.4 (C15, 1JC 266.2 Hz, 2JC 38.6 Hz), 88.2
F
F
(C2, 1JC 251.5 Hz, 2JC 25.7 Hz); GC/MS: 468
F
F
[M±F] (3), 195 [C3F7CN] (1), 169 [C3F7] (8), 150
[CF2=CF±CF3]
(10), 100 [CF2=CF2]
(10), 92
[C5H4N2] (2), 78 [C5H4N] (100), 69 [CF3] (26), 51
[HCCCN]
(14); HRMS(CI) Calc. 468.0056 for
C13H5F14N3; Found: 468.0068. 4-Fluoro-2,4-bis(hepta-
¯uoropropyl)-4H-pyrido-[1,2-a][1,3,5]triazine (22b)
(2.6 g, 13%); Mp 128±1298C (hexane). Elution with acetone
gave hepta¯uoro-butyramide (6) (1.4 g, 16%); Mp 82±848C
[21].
(C4), 150.1 (C6), 150.0 (C2, 2JC 35.0 Hz), 141.5 (C10),
F
128.1 (C8), 126.7 (C9), 119.6 (C7), 122.2 (C11,
1JC 272.8 Hz), 118.5 (C13, 1JC 286.9 Hz,
F
F
2JC 35.7 Hz),
111.4
(C12,
1JC 260.3 Hz,
F
F
2JC 36.0 Hz), 102.5 (C3, 2JC 33.4 Hz); GC/MS:
F
F
3.9. Reaction of perfluoro-2-methylpent-2-ene with
2-amino-pyridine
332 [M] (85), 313 [M±F] (25), 304 [M±N2] (51), 263
[M±CF3] (1), 235 (100), 213 [M±C2F5] (3), 119 [C2F5]
(1), 78 [C5H4N] (94), 69 [CF3] (5); HRMS(CI) Calc.
332.0196 for C11H4F8N2O; Found: 332.0185. Elution with
acetone gave penta¯uoro-N-pyridin-2-yl-propion-amide
(27) (0.8 g, 10%); Mp 121±1228C; 19F NMR ((CD3)2SO)
dF: 78.7 (3F), 52.3 (2F); Calc. C, 40.00; H, 2.08; F, 39.58; N,
11.67%; MS 240 for C8H5F5N2O; Found: C, 39.84; H, 2.12;
F, 39.10; N, 11.43%; MS 240.
Reaction of 1 (10.0 g, 33 mmol) with 2-aminopyridine
(3.1 g, 33 mmol) and triethylamine (10.0 g, 100 mmol) in
dry MeCN (30 ml) by Procedure A followed by distillation
of the crude product provided a yellow liquid (bp 110±
1128C/0.4 Torr, 11.2 g). The distillate was further puri®ed
on silica gel with CH2Cl2 to afford pyridin-2-yl-[3,3,3-
tri¯uoro-1-penta¯uoroethyl-2-tri¯uoromethyl-propenyl]
amine (24) (1.2 g, 10%) as a yellow liquid; 1H NMR
(CDCl3) d: 9.19 (H11, d, J 7 Hz), 8.20 (H10, t, J 7 Hz),
7.90 (H8, d, J 7 Hz), 7.57 (H9, t, J 7 Hz); 19F NMR
(CDCl3) dF: 104.8 (3F, F6, t, JF±F 21 Hz), 82.3 (2F, F5, s),
52.3 (2F, F4, q, JF±F 21 Hz); Calc. C, 35.29; H, 1.34; F,
55.88; N, 7.49%; MS 374 for C11H5F11N2; Found: C, 35.24;
H, 1.32; F, 56.07; N, 7.38%; MS 374. 2,4-Di¯uoro-2-
penta¯uoroethyl-3-tri¯uoromethyl-2H-pyrido[1,2-a]pyri-
midine (25) (7.5 g, 64%); Bp 110±1128C/0.4 Torr. The
isomers 25a,b have been puri®ed and isolated by column
chromatography on silica gel. IR 1240±1120 (C±F), 1320,
1415 (C±N), 1500, 1520, 1530 (C=CAr), 1630, 1710 (C=C),
2890 cm 1; lmax (EtOH)/nm 277 (e 1330), 366 (e 8800); 1H
NMR (CDCl3) d: 7.99 (H10, d, J 6.8 Hz), 7.79 (H7, d,
J 6.8 Hz), 7.21 (H8, t, J 6.8 Hz), 7.08 (H9, t,
J 6.8 Hz); 19F NMR (CDCl3) dF: 110.4 (3F, F11, td, JF±
3.10. Reaction of perfluoro-2-methylpent-2-ene and
perfluoro-5-azanon-4-ene with guanidine hydrochloride
Compound 1 (15.0 g, 0.05 mol), triethylamine (20.2 g,
0.2 mol) and dry ether (60 ml) were mixed together and
cooled to 08C with stirring. To the stirred reaction mixture
was added ®nely powdered guanidine hydrochloride
(4.75 g, 0.05 mol) in small portions. Stirring was continued
at 08C for 1 h and at room temperature for a further 24 h.
After this time, the solid material present was ®ltered off and
the ether washed with water (2 Â 100 ml), dried (MgSO4)
and the solvent removed by evaporation to leave 12.5 g
(83%) of a thick yellow oil. Column chromatography
(CH2Cl2-acetone 7 : 1 on silica gel) gave the pure com-
pound,
2-amino-4-¯uoro-6-penta¯uoroethyl-5-tri¯uoro-
methylpyrimidine (28) as a colorless solid, which was
recrystallized from CH2Cl2 to give colorless needles, mp
98±998C; IR 1224±1145 (C±F),1270, 1300, 1324, 1395
(C±N), 1517, 1544 (C=N), 1607, 1665 (C=C), 3350,
3454 (NH2) cm 1; lmax (EtOH)/nm 260 (e 23000), 300 (e
10.2, 25.2 Hz), 91.9 (1F, F2, q, JF±F 25.2 Hz), 82.6
F
(3F, F13, s), 43.6 and 37.6 (F12, 2F, AB-system JF±F
298.4Hz); 13C NMR (CD2Cl2) d: 161.7 (C2,
1JC 244.3 Hz), 150.1 (C10, 2JC 32.0 Hz), 139.9
F
F
(C9), 130.5 (C6), 122.6 (C8), 114.7 (C7), 122.0 (C11,
3400); 19F NMR ((CD3)2CO) dF: 109.4 (F, F4, q, JF±F
1JC 270.7 Hz), 116.9 (C13, 1JC 287.1 Hz,
19.9 Hz), 108.4 (3F, F7, q, JF±F 19.5 Hz), 82.7 (3F, F9, s),
F
F
12
1
2JC 37.7 Hz), 110.3 (C , JC 260.1 Hz, JC
52.0 (2F, F8, q, JF±F 19.5 Hz); H NMR ((CD3)2CO) d
1
2
F
F
F
4
1
2
36.2 Hz), 101.5 (C , JC 245.1 Hz, JC 29.3 Hz,
7.71 (NH2); 13C NMR (CD2Cl2) dF: 166.8 (C4, q, JC±F
F
F
2JC 12.5 Hz), 70.4 (C3, 2JC 32.3 Hz, 2JC
254.7 Hz), 162.8 (C , d, JC 21.6 Hz), 157.6 (C2, t,
6
3
F
F
F
F
32.3 Hz); GC/MS: 354 [M] (10), 335 [M±F] (10), 285
2JC 23.0 Hz), 121.3 (C7, qd, 1JC 270.9 Hz,
F
F