T. Itoh et al. / Tetrahedron 56 (2000) 4383±4395
4389
1
3
1,3-Di(ethoxycarbonyl)-2-(2-oxocyclohexyl)-4-imidazo-
line (2f). Colorless oil. H NMR (CDCl ) d: 1.19 (3H, t,
m), 7.50 (7.70) (2H, b). C NMR (CDCl ) d: 9.80 (CH ),
3 3
1
14.38 (2CH ), 44.64 (CH), 51.70 (CH ), 62.45 (2CH ),
3 3 2
3
J7.3 Hz), 1.20 (3H, t, J7.3 Hz), 1.60±1.84 (6H, m),
76.58 (CH), 114.98 (2CH), 123.55 (123.66) (2CH), 132.75
(2C), 151.75 (2CO), 172.09 (CO). HRMS (EI) m/z (M );
1
2
.22±2.29 (1H, m), 2.41±2.49 (1H, m), 2.63±2.65 (1H,
1
Calcd for C H N O : 350.1477. Found: 350.1462; (M -
m), 4.09 (2H, q, J7.3 Hz), 4.11 (2H, q, J7.3 Hz), 6.25
1
7
22
2
6
(
1H, d, J2.9 Hz), 6.26 (1H, d, J4.4 Hz), 6.31 (1H, d,
CHMeCO Me) calcd for C H N O : 263.1032. Found:
2 13 15 2 4
263.1007.
1
3
J2.9 Hz). C NMR (CDCl ) d: 14.14 (2CH ), 22.20
3
3
(
(
(
(
CH ), 25.04 (CH ), 25.59 (CH ), 53.84 (CH), 40.34
2 2 2
CH ), 61.56 (CH ), 61.65 (CH ), 71.84 (CH), 113.29
2
1,3-Di(1-chloroethoxycarbonyl)-2-[1-(methoxycarbonyl)-
2
2
0
1
ethyl]benzimidazoline (4b ). Colorless oil. H NMR
CH), 113.77 (CH), 150.42 (CO), 150.91 (CO),206.12
CO). HRMS (EI) m/z (M 2C H O); Calcd for
1
(CDCl ) d: 1.09±1.12 (3H, m), 1.87±1.94 (6H, m), 3.13±
3
6
9
C H N O : 213.0876. Found: 213.0871.
4
3.47 (1H, m), 3.59±3.64 (3H, m), 6.51±6.55 (1H, m), 6.63±
9
13
2
1
3
6
NMR spectrum was obtained as that of a mixture of at least
.70 (2H, m), 7.05±7.09 (2H, m), 7.50±7.70 (2H, bs).
C
1
imidazoline (2f ). Colorless oil. H NMR (CDCl ) d: 1.62±
,3-Di(1-chloroethoxycarbonyl)-2-(2-oxocyclohexyl)-4-
0
1
13
®ve isomers. C NMR (CDCl ) d: 10.00±10.46 (4 peaks)
3
3
2
2
.00 (6H, m), 1.81 (6H, t, J5.8 Hz), 2.29±2.35 (1H, m),
(CH ), 25.39±25.54 (4 peaks) (2CH ), 44.85 (CH), 51.81±
3
52.18 (5 peaks) (CH ), 76.66 (76.75, 76.84) (CH), 83.15±
3
3
.54±2.61 (1H, m), 2.74 (1H, bs), 6.26±6.30 (3H, m), 6.52
1
3
(
trum was obtained as that of a mixture of at least two
2H, q, J5.8 Hz), 6.54 (2H, q, J5.8 Hz). C NMR spec-
83.73 (4 peaks) (CH), 115.59 (115.69, 115.80) (2CH),
124.35±124.73 (6 peaks) (2CH), 130.81 (2C), 149.04
(2CO), 171.56 (171.60,171.63) (CO). HRMS (FAB1);
1
isomers. C NMR (CDCl ) d: 23.39 (23.67) (CH ), 25.14
3
3
2
3
5
1
(
(
25.26) (2CH ), 25.37 (25.47) (CH ), 26.22 (CH ), 40.99
3
41.18) (CH ), 55.10 (CH), 72.50 (CH), 82.97±83.18 (4
2
Calcd for C H Cl N O (M1H) : 419.0777. Found:
14 21 2 2 6
2
2
419.0780.
peaks) (2CH), 113.78 (CH), 114.04 (CH), 148.23 (2CO),
1
2
05.103 (CO). HRMS (EI) m/z (M ); Calcd for
1,3-Di(ethoxycarbonyl)-2-(2,5-dihydro-2-oxo-5-furyl)-
benzimidazoline (4c). Colorless oil. Anal. Calcd for
C H N O : C, 58.95; H, 5.24; N, 8.09. Found: C, 59.09;
5
C H Cl N O : 378.0749. Found: 378.0741.
1
5
20
2
2
5
1
7
18
2
6
1
1,3-Di(ethoxycarbonyl)-2-[1-methyl-1-(methoxycarbonyl)-
ethyl]benzimidazoline (4a). Colorless oil. Anal. Calcd for
H, 5.17; N, 8.14. H NMR (CDCl ) d: 1.36 (3H, t,
3
J7.0 Hz), 1.40 (3H, t, J7.2 Hz), 4.29 (2H, q,
J7.0 Hz), 4.36 (2H, q, J7.0 Hz), 5.49 (1H, bs), 6.05
(1H, dd, J5.5, 1.2 Hz), 6.46 (1H, d, J1.8 Hz), 6.97±
C H N O : C, 59.33; H, 6.64; N, 7.69. Found: C, 59.12; H,
2
1
8
24
6
1
.76; N, 7.54. H NMR (CDCl ) d: 1.15 (6H, s), 1.36 (6H, t,
6
3
1
3
J7.0 Hz), 3.56 (3H, s), 4.29 (2H, q, J7.0 Hz), 4.31 (2H,
7.04 (2H, m), 7.30±7.53 (3H, m). C NMR spectrum was
1
3
C
q, J7.0 Hz), 6.50 (1H, s), 7.01±7.03 (2H, m), 7.48±7.49
obtained as that of a mixture of at least ®ve isomers.
NMR (CDCl ) d: 14.31 (14.38) (2CH ), 62.85 (62.89)
1
3
(
2H, m), C NMR (CDCl ) d: 14.37 (CH ), 14.40 (CH ),
3 3 3
3
3
2
0.78 (2CH ), 49.94 (C), 51.94 (CH ), 62.47 (CH ), 62.56
3
(2CH ), 71.88 (CH), 82.81 (CH), 115.05 (115.25) (2CH),
2
3
2
(
(
(
CH ), 78.98 (CH), 116.28 (2CH), 123.89 (2CH), 133.81
2
121.62±122.27 (5 peaks) (CH), 123.79 (124.16) (2CH),
131.92 (132.11) (2C), 150.66 (150.69, 150.73) (CH),
152.31 (2CO), 171.67 (CO). HRMS (EI) m/z (M ); Calcd
2
1
2C), 152.84 (2CO), 174.59 (CO). IR (KBr) 1720 cm
±CCO ±), 1710 cm (±NCO ±). HRMS (EI) m/z (M );
2
1
1
1
2
2
Calcd for C H N O : 364.1634. Found: 364.1653;
6
for
C H N O :
346.1165.
Found:
346.1161;
(M 2C H O ) calcd for C H N O : 263.1032. Found:
1
8
24
2
17 18
2
6
1
M 2CMe CO Me) calcd for C H N O : 263.1032.
1
(
Found: 263.1043.
2
2
13 15
2
4
4
3
2
13 15
2
4
263.1003.
1,3-Di(1-chloroethoxycarbonyl)-2-[1-methyl-1-(methoxy-
carbonyl)ethyl]benzimidazoline (4a ). Colorless oil. Anal.
1,3-Di(1-chloroethoxycarbonyl)-2-(2,5-dihydro-2-oxo-5-
0
Calcd for C H Cl N O : C, 49.90; H, 5.12; N, 6.47.
0
1
furyl)benzimidazoline (4c ). Colorless oil. H NMR
(CDCl ) d: 1.88±1.97 (3H, m), 5.48±5.54 (1H, bs), 6.11±
3
1
8
22
2
2
6
1
Found: C, 50.04; H, 4.94; N, 6.41. H NMR (CDCl ) d:
6.12 (1H, m), 6.44±6.50 (1H, m), 6.61±6.74 (2H, m), 7.06±
7.13 (2H, m), 7.36±7.60 (3H, m). C NMR spectrum was
3
1
3
1
.18 (1.17) (6H, s), 1.88 (1.93) (6H, d, J5.8 Hz (dd,
1
3
C
J5.8, 2.4 Hz)), 3.57 (3.58, 3.55) (3H, s), 6.50 (6.49,
obtained as that of a mixture of at least ®ve isomers.
NMR (CDCl ) d: 25.25 (25.35) (2CH ), 74.25 (CH), 82.19
6
7
2
.51) (1H, s), 6.61±6.66 (2H, m), 7.08 (1H, t, J3.8 Hz),
3
3
1
3
.11 (1H, t, J3.8 Hz), 7.53 (2H, bs), C NMR (CDCl ) d:
(CH), 83.23 (83.28) (2CH), 115.13±115.50 (5 peaks)
(2CH), 124.50 (124.58) (CH), 124.84 (124.85, 124.90)
(2CH), 131.19 (2C), 150.15 (CH), 152.31 (2CO), 170.90
3
1.11 (21.00) (2CH ), 25.44 (25.33) (CH3), 29.74 (29.70)
3
(
(
(
CH3), 49.82 (49.80, 49.84) (CH ), 52.35 (52.38, 52.33)
3
C), 79.15 (79.00, 79.23) (CH), 83.17 (83.15) (CH), 83.30
83.28) (CH), 116.72 (116.67, 116.59, 116.50) (2CH),
3
5
(CO). HRMS (FAB1); Calcd for C H Cl N O
17 17 2 2 6
1
(M1H) : 415.0464. Found: 415.0485.
1
1
1
24.75 (124.71, 124.70, 124.67) (2CH), 132.82 (132.92,
32.76) (2C), 149.70 (149.80, 149.85) (2CO), 173.80,
2-Acetonyl-1,3-di(ethoxycarbonyl)benzimidazoline (4d).
Colorless oil. Anal. Calcd for C H N O : C, 59.99; H,
1
73.903) (CO). HRMS (EI) m/z (M ); Calcd for
1
6
20
2
5
5
1
6.29; N, 8.75. Found: C, 60.11; H, 6.09; N, 8.64. H NMR
C H Cl N O : 432.0855. Found: 432.0861.
1
8
22
2
2
6
(
CDCl ) d: 1.36 (6H, t, J7.0 Hz), 2.19 (3H, s), 2.97 (2H, d,
3
1,3-Di(ethoxycarbonyl)-2-[1-(methoxycarbonyl)ethyl]-
benzimidazoline (4b). Colorless oil. H NMR (CDCl ) d:
J4.6 Hz), 4.28±4.34 (4H, m), 6.41 (1H, t, J4.6 Hz),
1
13
6.96±7.00 (2H, m), 7.56 (2H, bs). C NMR (CDCl ) d:
3
3
1
.07 (3H, d, J7.3 Hz), 1.35 (3H, t, J7.3 Hz), 1.38 (3H, t,
J7.3 Hz), 3.11 (1H, qd, J7.3, 2.5 Hz), 3.63 (3H, s), 4.34
4H, q, J7.3 Hz), 6.50 (1H, d, J2.5 Hz), 6.97±7.01 (2H,
14.22 (2CH ), 30.11 (CH ), 48.69 (48.70) (CH ), 62.27
3
3
2
(2CH ), 72.67 (CH), 114.65 (2CH), 123.44 (2CH), 131.50
2
1
(2C), 151.08 (2CO), 202.76 (CO). HRMS (EI) m/z (M );
(