Med Chem Res
continuous stirring. The mixture was then refluxed for
3–4 h, the precipitated sodium chloride was filtered off,
and excess solvent was removed under vacuum. The sep-
arated solid was washed with dry n-hexane and recrystal-
lized from the mixture of dry ethanol and n-hexane (50:50
v/v) to ensure the purity of the product.
d = 5.71 (1H, C5–H), 7.25 (d, J = 9.3 Hz, 1H), 7.18 (d,
J = 9.3 Hz, 1H), 7.05 (s, 1H), 1.50 (t, J = 2.3 Hz, 4H),
0.99 (t, J = 4.3 Hz, 6H), 0.95–0.90 (m, 8H); 13C NMR
(CDCl3, 300 MHz): d = 163.8 (C, C2), d = 96.7 (C, C3),
188.5 (C, C4), 105.9 (C, C5), 162.0 (C, C6), 181.9 (C, C7),
19.5, 19.1 (C–CH3), 149.4, 126.9, 121.7, 118.9, 117.6,
117.2 (Ar–C), 13.3, 15.3, 20.6, 21.5 (Si–Bu); MS m/z:
414.9 C23H32NO4Si (calcd. 414.5); Anal. Calcd: C, 66.63;
H, 7.78; N, 3.38; Si, 6.77. Found: C, 66.95; H, 7.43; N,
3.26; Si, 6.66.
Et2Si(LI) (5): dark brown (EtOH); yield: 76 %; IR (KBr)
v max 1592, 600, 520 cm-1; 1H NMR (CDCl3, 300 MHz,):
d = 5.57 (1H, C5–H), 7.56 (d, J = 8.5 Hz, 1H), 7.11 (s,
1H), 6.98 (d, J = 8.5 Hz, 1H), 1.18 (t, J = 4.5 Hz, 6H),
1.01 (q, J = 4.5 Hz, 4H), 13C NMR (CDCl3, 300 MHz):
d = 163.8 (C, C2), 96.8 (C, C3), 188.1 (C, C4), 105.3 (C,
C5), 162.7 (C, C6), 183.0 (C, C7), 19.8, 19.3 (C–CH3),
151.0, 128.9, 126.8, 124.5, 121.9 118.5 (Ar–C), d = 9.2,
11.2 (Si–Et); MS m/z: 343.8 C18H22NO4Si (calcd. 344.4);
Anal. Calcd: C, 62.76; H, 6.82; N, 4.15; Si, 8.15. Found: C,
62.42; H, 6.44; N, 4.07; Si, 8.23.
Ph2Si(LII) (10): dark brown (EtOH): yield: 72 %; IR
(KBr) v max 1603, 636, 558 cm-1 1H NMR (CDCl3,
;
300 MHz,): d = 5.73 (1H, C5–H), 7.61 (d, J = 8.8 Hz,
1H), 7.01 (d, J = 8.8 Hz, 1H), 7.13 (s, 1H), 7.45–7.33 (m,
4H), 7.29–7.14 (m, 6H); 13C NMR (CDCl3, 300 MHz):
d = 163.9 (C, C2), 96.4 (C, C3), 189.8 (C, C4), 106.8 (C,
C5), 162.5 (C, C6), 182.7 (C, C7), 18.8, 18.6 (C–CH3),
150.1, 127.4, 122.6, 118.5, 117.8, 117.1 (Ar–C), 148.8,
138.1, 130.9, 121.8 (Si–Ph); MS m/z: 453.9 C27H24NO4Si
(calcd. 454.5); Anal. Calcd: C, 71.34; H, 5.32; N, 3.08; Si,
6.18. Found: C, 71.62; H, 5.61; N, 3.16; Si, 5.45.
Bu2Si(LI) (6): dark brown (EtOH); yield: 74 %; IR
(KBr) v max 1591, 630, 529 cm-1 1H NMR (CDCl3,
;
300 MHz,): d = 5.58 (1H, C5–H), 7.58 (d, J = 9.1 Hz,
1H), 7.19 (s, 1H), 7.05 (d, J = 9.1 Hz, 1H), 1.53
(J = 3.2 Hz, t, 4H), 1.09 (J = 5.1 Hz, t, 6H), 0.97–0.91(m,
8H); 13C NMR (CDCl3, 300 MHz): d = 163.9 (C, C2),
96.3 (C, C3), 188.5 (C, C4), 106.1 (C, C5), 163.1 (C, C6),
182.5 (C, C7), 19.9, 19.2 (C–CH3), 150.3, 129.6, 127.2,
124.9, 122.7, 118.9 (Ar–C), 13.6, 15.7, 20.5, 21.6 (Si–Bu);
MS m/z: 401.6 C22H30NO4Si (calcd. 400.5); Anal. Calcd:
C, 65.97; H, 7.55; N, 3.50; Si, 7.01. Found: C, 66.13; H,
7.83; N, 3.58; Si, 6.92.
Et2Si(LIII) (11): dark brown (EtOH); yield: 73 %; IR
(KBr) v max 1600, 636, 548 cm-1 1H NMR (CDCl3,
;
300 MHz,): d = 5.80 (1H, C5–H), 7.55 (d, J = 8.0 Hz,
1H), 7.13 (s, 1H), 7.11 (d, J = 8.0 Hz, 1H), 1.17 (J = 2.9,
t, 6H), 0.99 (q, J = 2.9, 4H); 13C NMR (CDCl3,
300 MHz): d = 163.9 (C, C2), 96.8 (C, C3), 188.7 (C, C4),
107.0 (C, C5), 162.8 (C, C6), 183.7 (C, C7), 19.9, 19.4 (C–
CH3), 150.3, 128.7, 128.0, 124.5, 122.7, 119.4 (Ar–C), 9.3,
11.1 (Si–Et); MS m/z: 390.1 C18H21N2O6Si (calcd. 389.4);
Anal. Calcd: C, 55.51; H, 5.43; N, 7.19; Si, 7.21. Found: C,
55.83; H, 5.89; N, 7.08; Si, 6.94.
Ph2Si(LI) (7): brown (EtOH); yield: 78 %; IR (KBr)
v max 1593, 650, 540 cm-1; 1H NMR (CDCl3, 300 MHz,):
d = 5.58 (1H, C5–H), 7.64 (d, J = 7.8 Hz, 1H), 7.20 (s,
1H), 7.10 (d, J = 7.8 Hz, 1H), 7.53–7.46 (m, 4H),
7.30–7.24 (m, 6H); 13C NMR (CDCl3, 300 MHz):
d = 163.3 (C, C2), 97.7 (C, C3), 189.3 (C, C4), 106.5 (C,
C5), 163.3 (C, C6), 183.8 (C, C7), 19.6, 19.0 (C–CH3),
150.8, 130.7, 127.8, 124.7, 123.4, 119.3 (Ar–C), 147.3,
137.5, 133.6, 128.2 (Si–Ph); MS m/z: 441.6 C26H22NO4Si
(calcd. 440.5); Anal. Calcd: C, 70.88; H, 5.03; N, 3.18; Si,
6.38. Found: C, 71.03; H, 5.32; N, 2.50; Si, 5.67.
Bu2Si(LIII) (12): dark brown (EtOH); yield: 74 %; IR
(KBr) v max 1599, 647, 538 cm-1 1H NMR (CDCl3,
;
300 MHz,): d = 5.81 (1H, C5–H), 7.56 (d, J = 8.9 Hz,
1H), 7.18 (s, 1H), 6.99 (d, J = 8.9 Hz, 1H), 1.60 (t,
J = 4.1 Hz, 4H), 1.19 (t, J = 3.8 Hz, 6H), 0.98–0.92 (m,
8H); 13C NMR (CDCl3, 300 MHz): d = 163.7 (C, C2),
96.5 (C, C3), 189.6 (C, C4), 106.9 (C, C5), 162.6 (C, C6),
184.2 (C, C7), 20.1, 19.6 (C–CH3), 152.1, 129.2, 128.7,
125.1, 123.1, 119.6 (Ar–C), 14.1, 15.0, 20.2, 21.9 (Si–Bu);
MS m/z: 445.9 C22H29NO6Si (calcd. 445.0); Anal. Calcd:
C, 59.30; H, 6.56; N, 6.29; Si, 6.30. Found: C, 59.63; H,
6.82; N, 6.15; Si, 5.83.
Et2Si(LII) (8): brown (EtOH); yield: 74 %; IR (KBr)
v max 1599, 656, 556 cm-1;1H NMR (CDCl3, 300 MHz,):
d = 5.72 (1H, C5–H), 7.20 (d, J = 8.9 Hz, 1H), 7.08 (d,
J = 8.9 Hz, 1H), 6.95 (s, 1H), 1.12 (J = 4.6 Hz, t, 6H),
0.98 (J = 4.6 Hz, q, 4H); 13C NMR (CDCl3, 300 MHz):
d = 163.5 (C, C2), 96.9 (C, C3), 188.9 (C, C4), 106.1 (C,
C5), 162.3 (C, C6), 182.0 (C, C7), 19.9, 19.2 (C–CH3),
151.9, 127.8, 123.1, 119.2, 118.1 117.5 (Ar–C), 9.1, 10.9
(Si–Et); MS m/z: 357.8 C19H24NO4Si (calcd. 358.4); Anal.
Calcd: C, 63.66; H, 6.75; N, 3.91; Si, 7.83. Found: C,
63.92; H, 6.53; N, 3.40; Si, 7.70.
Ph2Si(LIII) (13): brown (EtOH); yield: 76 %; IR (KBr)
v max 1601, 650, 528 cm-1; 1H NMR (CDCl3, 300 MHz,):
d = 5.82 (1H, C5–H), 7.67 (d, J = 9.0 Hz, 1H), 7.21 (s,
1H), 7.19 (d, J = 9.0 Hz, 1H), 7.56–7.46 (m, 4H),
7.27–7.22 (m, 6H); 13C NMR (CDCl3, 300 MHz):
d = 163.8 (C, C2), 96.9 (C, C3), 190.1 (C, C4), 107.2 (C,
C5), 162.8 (C, C6), 184.9 (C,C7), 20.4, 19.5 (C–CH3),
151.9, 129.6, 128.9, 125.2, 123.4, 119.9 (Ar–C), 149.5,
139.7, 133.2, 130.6 (Si–Ph); MS m/z: 485.9 C26H21NO6Si
Bu2Si(LII) (9): brown (EtOH); yield: 77 %; IR (KBr)
v max 1600, 639, 560 cm-1; 1H NMR (CDCl3, 300 MHz,):
123