T. Hanamoto et al. / Journal of Fluorine Chemistry 128 (2007) 1126–1130
1129
solid (542.5 mg, 84%): mp 62.8–64.0 8C; IR (KBr) 3170, 3103,
2956, 1503, 1351, 1257, 1085, 954, 846 cmꢀ1 1H NMR
2.0 Hz), 7.88 (1H, dd, J = 4.8, 0.6 Hz), 8.13 (2H, dt, J = 8.8,
2.0 Hz); 19F NMR (CDCl3) ꢀ174.9 (1F, t, J = 4.1 Hz); 13C
NMR (CDCl3) 14.3, 61.2, 112.9 (d, J = 28.0 Hz), 117.7, 128.5,
129.5 (d, J = 13.7 Hz), 131.1, 143.1, 151.3 (d, J = 250.4 Hz),
165.7; GC–MS m/z 234 (34, M+), 189 (100), 161 (15), 134 (56),
107 (63), 76 (37), 50 (32); Anal. Calcd. for C12H11FN2O2: C,
61.53; H, 4.73; N, 11.96. Found: C, 61.48; H, 4.79; N, 11.94%.
;
(CDCl3) 0.38 (9H, s), 7.46 (1H, d, J = 4.6 Hz), 9.85 (1H, brs);
19F NMR (CDCl3) ꢀ175.4 (1F, d, J = 3.6 Hz); 13C NMR
(CDCl3) ꢀ1.63, 125.7 (d, J = 18.1 Hz), 127.3 (d, J = 34.3 Hz),
156.9 (d, J = 242.9 Hz); GC–MS m/z 158 (14, M+), 143 (100),
142 (28), 89 (21), 88 (48), 81 (43), 77 (27), 73 (27), 63 (34), 54
(25); Anal. Calcd. for C6H11FN2Si: C, 45.54; H, 7.01; N, 17.70.
Found: C, 45.20; H, 6.85; N, 17.55%.
4.5. 4-Fluoro-1-(40-trifluoromethylphenyl)pyrazole (5d)
4.2. 4-Fluoro-1-phenylpyrazole (5a)
White solid; yield 86%; mp 60.2–61.1 8C; IR (KBr) 3145,
3085, 1621, 1606, 1529, 1410, 1328, 1168, 1134, 1070, 1019,
942, 856, 831, 779, 716 cmꢀ1; 1H NMR (CDCl3) 7.62 (1H, d,
J = 4.2 Hz), 7.71 (2H, brd, J = 9.0 Hz), 7.76 (2H, brd,
J = 9.0 Hz), 7.86 (1H, d, J = 4.8 Hz); 19F NMR (CDCl3)
ꢀ64.4 (3F, s), ꢀ174.5 (1F, t, J = 4.8 Hz); 13C NMR (CDCl3)
112.9 (d, J = 28.6 Hz), 118.3, 122.1, 123.9 (q, J = 271.5 Hz),
126.8 (d, J = 3.7 Hz), 128.6 (q, J = 33.0 Hz), 129.7 (d,
J = 13.7 Hz), 142.0, 151.5 (d, J = 251.0 Hz); GC–MS m/z
230 (90, M+), 145 (100), 134 (39), 125 (45), 107 (37), 95 (73),
75 (65), 69 (21), 50 (28); Anal. Calcd. for C10H6F4N2: C, 52.18;
H, 2.63; N, 12.17. Found: C, 52.33; H, 2.71; N, 12.14%.
To a solution containing CuI (6.8 mg, 0.0375 mmol) and 2-
pyridine-aldoxime (8.7 mg, 0.0712 mmol) in CH3CN (1.5 mL)
was successively added the pyrazole 1 (56.5 mg, 0.375 mmol),
Cs2CO3 (233.5 mg, 0.717 mmol) and iodobenzene (47.9 mL,
0.428 mmol). The reaction mixture was heated to 60 8C, and
stirred for 24 h. The reaction mixture was cooled to room
temperature and diluted with hexane/ethyl acetate = 3/1. After
filtration of a mixture through a plug of celite, the filter cake
being further washed with hexane/ethyl acetate = 3/1. The
combined filtrate was concentrated under reduced pressure. The
residue was purified by silica gel column chromatography
(hexane/ethyl acetate/triethylamine = 180/20/1 then 150/50/1)
to give the desired compound (5a) as a white solid (43.7 mg,
76%): mp 37.5–38.2 8C; IR (KBr) 3130, 3108, 1599, 1582,
4.6. 4-Fluoro-1-(40-nitrophenyl)pyrazole (5e)
White solid; yield 98%; mp 144.3–145.0 8C; IR (KBr) 3143,
1505, 1411, 1370, 1016, 944, 839, 752, 688 cmꢀ1; H NMR
1593, 1525, 1409, 1336, 1180, 1112, 1017, 937, 847, 750 cmꢀ1
;
1
(CDCl3) 7.25–7.33 (1H, m), 7.40–7.50 (2H, m), 7.57 (1H, d,
J = 4.2 Hz), 7.60 (1H, q, J = 1.1 Hz), 7.63 (1H, q, J = 1.1 Hz),
7.80 (1H, dd, J = 4.8, 0.7 Hz); 19F NMR (CDCl3) ꢀ175.9 (1F,
d, J = 4.8 Hz); 13C NMR (CDCl3) 112.9 (d, J = 28.0 Hz),
118.7, 126.7, 128.5 (d, J = 13.7 Hz), 129.5, 140.1, 151.2 (d,
J = 248.5 Hz); GC–MS m/z 162 (62, M+), 161 (27, M+ ꢀ 1),
136 (16), 108 (71), 107 (47), 77 (100), 51 (59); Anal. Calcd. for
C9H7FN2: C, 66.66; H, 4.35; N, 17.27. Found: C, 66.75; H,
4.31; N, 17.30%.
1H NMR (CDCl3) 7.67 (1H, d, J = 4.2 Hz), 7.82 (2H, dt,
J = 9.4, 2.8 Hz), 7.92 (1H, dd, J = 4.7, 0.7 Hz), 8.34 (2H, dt,
J = 9.4, 2.8 Hz); 19F NMR (CDCl3) ꢀ172.9 (1F, t, J = 4.2 Hz);
13C NMR (CDCl3) 113.0 (d, J = 28.6 Hz), 118.13, 118.14,
125.4, 130.8 (d, J = 13.7 Hz), 144.2, 145.7, 151.8 (d,
J = 252.9 Hz); GC–MS m/z 207 (38, M+), 134 (67), 108
(20), 107 (100), 76 (54), 75 (56), 63 (60), 50 (64); Anal. Calcd.
for C9H6FN3O2: C, 52.18; H, 2.92; N, 20.28. Found: C, 52.31;
H, 2.88; N, 20.28%.
4.3. 1-(40-Acetylphenyl)-4-fluoropyrazole (5b)
4.7. 1-(40-Cyanophenyl)-4-fluoropyrazole (5f)
White solid; yield 82%; mp 133.4–134.6 8C; IR (KBr) 3113,
White solid; yield 98%; mp 124.0–125.0 8C; IR (KBr) 3063,
1680, 1599, 1414, 1275, 1188, 1114, 1020, 947, 844, 831 cmꢀ1
;
2229, 1600, 1524, 1412, 1183, 1167, 1018, 939, 837, 779 cmꢀ1
;
1H NMR (CDCl3) 2.63 (3H, s), 7.63 (1H, d, J = 4.2 Hz), 7.73
(2H, brd, J = 8.8 Hz), 7.89 (1H, d, J = 4.8 Hz), 8.06 (2H, brd,
1H NMR (CDCl3) 7.65 (1H, d, J = 4.0 Hz), 7.76 (4H, s), 7.87
(1H, d, J = 5.0 Hz); 19F NMR (CDCl3) ꢀ173.7 (1F, t,
J = 3.7 Hz); 13C NMR (CDCl3) 109.9, 112.8 (d, J = 28.6 Hz),
118.2, 118.4, 130.3 (d, J = 14.3 Hz), 133.6, 142.8, 151.6 (d,
J = 251.6 Hz); GC–MS m/z 187 (23, M+), 133 (36), 115(13), 102
(100), 75 (38), 51 (22); Anal. Calcd. for C10H6FN3: C, 64.17; H,
3.23; N, 22.45. Found: C, 64.11; H, 3.23; N, 22.45%.
J = 8.8 Hz); 19F NMR (CDCl3) ꢀ174.9 (1F, d, J = 4.3 Hz); 13
C
NMR (CDCl3) 26.5, 112.9 (d, J = 28.6 Hz), 117.9, 129.8 (d,
J = 14.3 Hz), 130.0, 135.1, 143.2, 151.5 (d, J = 251.0 Hz),
196.4; GC–MS m/z 204 (33, M+), 189 (100), 188 (20), 161 (19),
134 (76), 133 (27), 107 (75), 76 (48), 63 (48), 50 (53); Anal.
Calcd. for C11H9FN2O: C, 64.70; H, 4.44; N, 13.72. Found: C,
64.69; H, 4.32; N, 13.82%.
4.8. 4-Fluoro-1-(30-methoxylphenyl)pyrazole (5g)
4.4. 1-(40-Ethoxycarbonylphenyl)-4-fluoropyrazole (5c)
White solid; yield 67%; mp 55.6–56.1 8C; IR (KBr) 3115,
3100, 1596, 1505, 1411, 1376, 1263, 1248, 1210, 1056, 1024,
957, 848, 766 cmꢀ1; 1H NMR (CDCl3) 3.86 (3H, s), 6.84 (1H,
ddd, J = 8.1, 2.2, 0.9 Hz), 7.15 (1H, ddd, J = 8.1, 2.2, 0.9 Hz),
7.24 (1H, t, J = 2.2 Hz), 7.33 (1H, t, J = 8.1 Hz), 7.56 (1H, brd,
J = 4.8 Hz), 7.78 (1H, dd, J = 4.8, 0.6 Hz); 19F NMR (CDCl3)
White solid; yield 76%; mp 95.2–96.2 8C; IR (KBr) 3124,
2982, 1707, 1614, 1583, 1413, 1282, 1110, 1021, 942, 854,
769 cmꢀ1; 1H NMR (CDCl3) 1.41 (3H, t, J = 7.2 Hz), 4.40 (2H,
q, J = 7.2 Hz), 7.62 (1H, d, J = 4.2 Hz), 7.70 (2H, dt, J = 8.8,