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3.4.11. 1-Benzyl-5-(tert-butyldiphenylsilyl)-3-methyl-
pyrazole (4i). Yield 80%; oil, Rf 0.52 (CH2Cl2); IR (film)
1428, 1107, 820, 731, 702 cmK1; 1H NMR (CDCl3) d 1.16 (s,
9H), 2.44 (s, 3H), 4.84 (s, 2H), 6.71 (s, 1H), 6.98–7.60 (m,
15H); 13C NMR (CDCl3) d 13.37, 18.51, 27.78, 55.51,
116.88, 126.62, 126.77, 127.53, 127.77, 129.39, 132.70,
135.95, 137.23, 137.87, 148.40. Anal. Calcd for C27H30N2Si:
C, 78.97; H, 7.36; N, 6.82. Found: C, 79.10; H, 7.24; N, 6.75.
1107, 700 cmK1; 1H NMR (CDCl3) d 1.11 (s, 9H), 2.04 (s,
3H), 3.37 (s, 2H), 5.21 (br, 1H), 5.50 (s, 1H), 6.81 (br, 1H),
7.30–7.55 (m, 10H); 13C NMR (CDCl3) d 11.07, 13.51,
18.43, 27.58, 109.03, 127.36, 129.13, 133.72, 136.04,
145.37, 150.09, 152.74. Anal. Calcd for C22H27N3OSi: C,
69.99; H, 7.21; N, 11.13. Found: C, 70.20; H, 7.26; N, 10.99.
3.4.19. 1-Ethyl-3-methyl-5-(methyldiphenylsilylmethyl)-
pyrazole (7d). Yield 93%; bp 200–205 8C/1 mmHg; IR
1
3.4.12. 5-(tert-Butyldiphenylsilyl)-3-methyl-1-phenyl-
pyrazole (4k). Yield 75%; mp 145–146 8C (from hexane);
(film) 1540, 1427, 1113, 808, 733, 700 cmK1; H NMR
(CDCl3) d 0.62 (s, 3H), 1.22 (t, JZ7.2 Hz, 3H), 2.20 (s, 3H),
2.52 (s, 2H), 3.71 (q, JZ7.2 Hz, 2H), 5.56 (s, 1H),
7.36–7.52 (m, 10H); 13C NMR (CDCl3) d K4.48, 13.27,
13.50, 15.29, 42.90, 104.06, 127.92, 129.60, 134.39, 135.48,
138.71, 147.00. Anal. Calcd for C20H24N2Si: C, 74.95;
H, 7.55; N, 8.74. Found: C, 75.24; H, 7.50; N, 8.53.
IR (KBr) 1599, 1499, 1108, 817, 704 cmK1 1H NMR
;
(CDCl3) d 1.04 (s, 9H), 2.46 (s, 3H), 6.87 (s, 1H), 6.88–7.49
(m, 15H); 13C NMR (CDCl3) d 13.21, 18.71, 28.08, 118.57,
126.34, 127.27, 127.52, 127.98, 129.18, 133.43, 135.89,
138.56, 141.86, 148.84. Anal. Calcd for C26H28N2Si:
C, 78.74; H, 7.12; N, 7.06. Found: C, 78.46; H, 7.02; N, 7.26.
3.4.20. 3-Methyl-5-(methyldiphenylsilylmethyl)pyra-
zole-1-carboxamide (7e). Yield 79%; mp 113–114 8C; IR
(KBr) 3461, 3304, 3248, 1727, 1562, 1427, 1387, 1113, 732,
3.4.13. 4,5-Dihydro-5-hydroxy-3,5-dimethyl-4-(tri-
methylsilylmethyl)pyrazole-1-carboxamide (5). H NMR
(CDCl3) d K0.20 (s, 9H), 0.85 (dd, 1H, JZ8.3, 14.8 Hz),
1.11 (dd, 1H, JZ6.6, 14.8 Hz), 1.77 (s, 3H), 2.14 (s, 3H),
3.43 (dd, 1H, JZ6.6, 8.3 Hz), 5.62 (br, 1H), 7.05 (br, 1H).
1
1
699 cmK1; H NMR (CDCl3) d 0.54 (s, 3H), 2.15 (s, 3H),
3.23 (s, 2H), 5.24 (br, 1H), 5.62 (s, 1H), 6.98 (br, 1H),
7.33–7.65 (m, 10H); 13C NMR (CDCl3) d K4.62, 13.58,
15.86, 108.55, 127.75, 129.36, 134.57, 135.87, 145.38,
150.50, 152.61. Anal. Calcd for C19H21N3OSi: C, 68.02;
H, 6.31; N, 12.53. Found: C, 67.93; H, 6.40; N, 12.65.
3.4.14. 3,5-Dimethyl-4-(trimethylsilylmethyl)-1-phenyl-
pyrazole (6a). Yield 72%; mp 190–191 8C (from hexane);
IR (KBr) 1598, 1502, 1364, 1246, 857, 760, 696 cmK1
;
1H NMR (CDCl3) d 0.47 (s, 9H), 1.76 (s, 2H), 2.18 (s, 3H),
2.22 (s, 3H), 7.45–7.47 (m, 5H); 13C NMR (CDCl3) d K1.56,
11.31, 11.96, 12.48, 115.22, 124.01, 126.32, 128.51, 133.81,
139.90, 146.67. Anal. Calcd for C15H22N2Si: C, 69.71;
H, 8.58; N, 10.84. Found: C, 70.00; H, 8.41; N, 10.80.
3.4.21. 1-(tert-Butyl-5-(tert-butyldiphenylsilylmethyl))-3-
methylpyrazole (7f). Yield 85%; oil, Rf 0.45 (CH2Cl2); IR
(film) 1653, 1540, 1471, 1427, 1236, 1106, 1011, 820, 734,
1
700 cmK1; H NMR (CDCl3) d 1.10 (s, 9H), 1.61 (s, 9H),
2.01 (s, 3H), 2.85 (s, 2H), 5.46 (s, 1H), 7.35–7.80 (m, 10H);
13C NMR (CDCl3) d 10.73, 13.48, 18.35, 27.79, 30.61,
58.94, 108.11, 127.59, 129.29, 133.60, 135.91, 138.48,
144.47. Anal. Calcd for C25H34N2Si: C, 76.87; H, 8.77;
N, 7.17. Found: C, 76.99; H, 8.73; N, 7.22.
3.4.15. 3,5-Dimethyl-4-(trimethylsilylmethyl)pyrazole-1-
carboxamide 6b. Yield 78%; mp 103–104 8C (from
hexane); IR (KBr) 3431, 3332, 1731, 1700, 1400, 863,
1
575 cmK1; H NMR (CDCl3) d 0.01 (s, 9H), 1.69 (s, 2H),
2.12 (s, 3H), 2.42 (s, 3H), 5.33 (br, 1H), 7.07 (br, 1H);
13C NMR (CDCl3) d K1.32, 12.30, 12.47, 12.86, 118.60,
137.38, 149.69, 152.65. Anal. Calcd for C10H19N3OSi:
C, 53.29; H, 8.50; N, 18.65. Found: C, 53.57; H, 8.49;
N, 18.40.
3.4.22. 5-(tert-Butyldiphenylsilylmethyl)-1-ethyl-3-
methylpyrazole (7g). Yield 91%; mp 45–47 8C; IR (KBr)
1540, 1470, 1427, 1107, 732, 701 cmK1; 1H NMR (CDCl3)
d 1.12 (s, 9H), 1.21 (t, 3H, JZ7.2 Hz), 2.09 (s, 3H), 2.59
(s, 2H), 3.64 (q, 2H, JZ7.2 Hz), 5.44 (s, 1H), 7.31–7.55
(m, 10H); 13C NMR (CDCl3) d 8.70, 13.43, 15.15, 18.23,
27.63, 42.70, 104.69, 127.56, 129.36, 133.34, 135.82,
138.62, 146.65. Anal. Calcd for C23H30N2Si: C, 76.19;
H, 8.34; N, 7.73. Found: C, 76.23; H, 8.40; N, 7.68.
3.4.16. 1,3-Dimethyl-5-(trimethylsilylmethyl)pyrazole
7a. Yield 40%; oil, bp 100–105 8C/0.2 mmHg; IR (film)
1
1542, 1249, 852 cmK1; H NMR (CDCl3) d 0.01 (s, 9H),
1.93 (s, 2H), 2.16 (s, 3H), 3.61 (s, 3H), 5.61 (s, 1H);
13C NMR (CDCl3) d K1.74, 13.31, 15.55, 35.53, 103.10,
141.25, 146.91. Anal. Calcd for C9H18N2Si: C, 59.28;
H, 9.95; N, 15.36. Found: C, 59.42; H, 10.00; N, 15.22.
3.4.23. 5-(tert-Butyldiphenylsilylmethyl)-3-methyl-1-
phenylpyrazole (7h). Yield 89%; oil, bp 250 8C/
0.5 mmHg; IR (film) 1598, 1501, 1107, 732, 699 cmK1
;
1H NMR (CDCl3) d 0.96 (s, 9H), 2.12 (s, 3H), 2.68 (s, 2H),
5.51 (s, 1H), 7.13–7.51 (m, 15H); 13C NMR (CDCl3) d 9.26,
13.48, 18.19, 27.50, 105.92, 126.04, 127.42, 127.59, 128.78,
129.37, 133.47, 135.94, 139.61, 140.36, 148.53. Anal. Calcd
for C27H30N2Si: C, 78.97; H, 7.36; N, 6.82. Found: C, 79.08;
H, 7.29; N, 6.93.
3.4.17. 5-(tert-Butyldiphenylsilylmethyl)-1,3-dimethyl-
pyrazole (7b). Yield 51%; mp 70–71 8C; IR (KBr) 1543,
1426, 1106, 734, 702 cmK1 1H NMR (CDCl3) d 1.11
;
(s, 9H), 2.07 (s, 3H), 2.56 (s, 2H), 3.23 (s, 3H), 5.47 (s, 1H),
7.31–7.52 (m, 10H); 13C NMR (CDCl3) d 9.25, 13.35,
18.24, 27.63, 35.18, 104.50, 127.60, 129.43, 133.28, 135.86,
139.62, 145.61. Anal. Calcd for C22H28N2Si: C, 75.81;
H, 8.10; N, 8.04. Found: C, 75.99; H, 8.00; N, 8.18.
3.4.24. 5-(tert-Butyldiphenylsilylmethyl)-3-isopropyl-1-
phenylpyrazole (7i). Yield 60%; oil, Rf 0.45 (CH2Cl2);
IR (film) 1598, 1501, 1380, 1106, 733, 699 cmK1; 1H NMR
(CDCl3) d 0.97 (s, 9H), 1.13 (d, JZ6.9 Hz, 6H), 2.72
(s, 2H), 2.87 (m, JZ6.9 Hz, 1H), 5.51 (s, 1H), 7.12–7.46
(m, 15H); 13C NMR (CDCl3) d 9.51, 18.12, 22.76, 27.44,
3.4.18. 5-(tert-Butyldiphenylsilylmethyl)-3-methyl-
pyrazole-1-carboxamide (7c). Yield 75%; mp
106–108 8C; IR (KBr) 3401, 3236, 1690, 1590, 1395,