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J. T. Kuethe et al. / Tetrahedron 63 (2007) 11489–11502
2H), 2.42 (m, 2H), 5.99 (s, 1H), 7.05 (m, 3H), 7.14 (m, 1H),
10.56 (br s, 1H); 13C NMR (CDCl3, 100 MHz) d 21.7, 22.7,
24.8, 26.9, 108.7, 109.9, 121.2, 121.6, 127.8, 128.4, 130.7,
132.2, 155.0. Anal. Calcd for C13H14N2O: C, 72.87; H,
6.59; N, 13.07. Found: C, 72.93; H, 6.58; N, 12.92.
7.67 (m, 3H), 11.2 (br s, 1H); 13C NMR (DMSO-d6,
100 MHz) d 26.9, 28.6, 41.0, 42.3, 79.7, 108.6, 110.7,
123.2, 124.8, 128.9, 129.0, 129.8, 130.5, 130.8, 132.5,
134.1, 138.5, 153.6, 154.4, 195.4. Anal. Calcd for
C29H25N3O4: C, 68.72; H, 6.01; N, 10.02. Found: C, 68.69;
H, 5.98; N, 9.95.
4.3.9. Preparation of 4-(5,6-dichloro-2-oxo-2,3-dihydro-
benzimidazol-1-yl)-2,6-dihydro-2H-pyridine-1-carb-
oxylic acid tert-butyl ester (54). According to the general
procedure, treatment of 616 mg (1.55 mmol) of 35 with
184 mg (0.62 mmol) of triphosgene in the presence of
1.07 g (7.75 mmol) of K2CO3 afforded 339 mg (57%) of
The second product to elute from the column (256 mg, 37%)
was identified as 4-(6-benzoly-2,3-dihydro-benzimidazol-
1-yl)-3,6-dihydro-2H-pyridin-1-carboxylic acid tert-butyl
ester (58) and was obtained as a colorless solid; mp
1
237 ꢀC (decomp.). H NMR (DMSO-d6, 400 MHz) d 1.39
1
54 as a colorless solid; mp 208–209 ꢀC. H NMR (CDCl3,
(s, 9H), 2.46 (m, 2H), 3.58 (m, 2H), 4.03 (m, 2H), 5.98 (s,
1H), 7.09 (d, 1H, J¼8.1 Hz), 7.39 (m, 2H), 7.49 (m, 2H),
7.64 (m, 3H), 11.42 (br s, 1H); 13C NMR (DMSO-d6,
100 MHz) d 26.9, 28.6, 41.0, 42.3, 79.7, 108.9, 109.6,
123.6, 126.0, 128.9, 129.8, 130.2, 130.4, 130.6, 132.5,
133.3, 138.4, 153.6, 154.4, 195.3. Anal. Calcd for
C29H25N3O4: C, 68.72; H, 6.01; N, 10.02. Found: C, 68.47;
H, 5.83; N, 9.86.
400 MHz) d 1.51 (s, 9H), 2.54 (m, 2H), 3.73 (t, 2H,
J¼5.0 Hz), 4.17 (m, 2H), 5.93 (s, 1H), 7.08 (s, 1H), 7.19
(s, 1H), 10.76 (br s, 1H); 13C NMR (CDCl3, 100 MHz)
d 26.9, 28.4, 41.0, 42.3, 80.3, 110.2, 111.4, 123.9, 125.1,
125.5, 127.6, 129.3, 131.0, 154.4, 154.6. Anal. Calcd for
C17H19Cl2N3O3: C, 53.14; H, 4.98; N, 10.94. Found: C,
52.76; H, 4.65; N, 10.91.
4.3.10. Preparation of (1S*5R*)-1-(8-methyl-8-aza-bicy-
clo[3.2.1]oct-2-en-3-yl)-1,3-dihydro-benzimidazol-2-one
(55). According to the general procedure, treatment of
500 mg (2.18 mmol) of 33 with 259 mg (3.44 mmol) of tri-
phosgene in the presence of 1.51 g (10.9 mmol) of K2CO3
afforded 345 mg (62%) of 55 as a tan solid; mp 203 ꢀC (de-
4.3.13. Rearrangement of spiro-benzimidazoline 41.
According to the general procedure, treatment of 1.00 g
(3.30 mmol) of 41 with 391 mg (1.32 mmol) of triphosgene
in the presence of 2.28 g (16.5 mmol) of K2CO3 was fol-
lowed by chromatography on silica gel. The first product
to elute from the column (330 mg, 30%) was identified as
4-(7-methyl-2-oxo-2,3-dihydro-benzimidazol-1-yl)-3,6-di-
hydro-2H-pyridine-1-carboxylic acid tert-butyl ester (59)
1
comp.). H NMR (CDCl3, 400 MHz) d 1.88 (m, 1H), 2.09
(m, 1H), 2.16–2.32 (m, 3H), 2.58 (s, 3H), 2.86 (d, 1H,
J¼17.5 Hz), 3.46 (m, 1H), 3.56 (t, 1H, J¼5.4 Hz), 6.04 (d,
1H, J¼5.4 Hz), 7.03 (m, 4H), 10.80 (br s, 1H); 13C NMR
(CDCl3, 100 MHz) d 30.1, 32.4, 34.5, 36.0, 57.3, 58.7,
108.6, 109.8, 121.3, 121.8, 128.6, 128.8, 129.4, 130.4,
154.7. Anal. Calcd for C15H17N3O: C, 70.56; H, 6.71; N,
16.46. Found: C, 70.51; H, 6.66; N, 16.43.
1
and was obtained as a colorless foam. H NMR (CDCl3,
400 MHz) d 1.51 (s, 9H), 2.35 (s, 3H), 2.40 (m, 1H), 2.67
(m, 1H), 3.77 (m, 3H), 4.17 (m, 2H), 6.81 (s, 1H), 6.81 (d,
1H, J¼7.1 Hz), 6.98 (m, 2H), 10.82 (br s, 1H); 13C NMR
(CDCl3, 100 MHz) d 17.7, 28.5, 29.4, 39.9, 43.2, 80.2,
108.0, 119.7, 121.8, 124.5, 126.5, 128.2, 128.8, 132.4,
154.9, 155.4. Anal. Calcd for C18H23N3O3: C, 65.63; H,
7.04; N, 12.76. Found: C, 65.48; H, 6.73; N, 12.56.
4.3.11. Preparation of 4-(2-oxo-2,3,3a,9b-tetrahydro-
perimidin-1-yl)-3,6-dihydro-2H-pyridine-1-carboxylic
acid ethyl ester (56). According to the general procedure,
treatment of 1.00 g (3.21 mmol) of 37 with 760 mg
(2.56 mmol) of triphosgene in the presence of 1.33 g
(9.63 mmol) K2CO3 afforded 659 mg (61%) of 56 as a light
The second product to elute from the column (235 mg, 22%)
was identified as 6-methyl-11-oxo-1,3,4,10,11,11a-hexahy-
dro-pyrid[4,3-b]benzodiazepine-2-carboxylic acid tert-
butyl ester (60) and was obtained as a colorless solid; mp
1
1
gray solid; mp 199–201 ꢀC. H NMR (CDCl3, 400 MHz)
201–202 ꢀC. H NMR (CDCl3, 400 MHz) d 1.48 (s, 9H),
d 1.33 (t, 3H, J¼7.1 Hz), 2.46 (m, 2H), 3.87 (br m, 2H),
4.24 (m, 4H), 5.95 (s, 1H), 6.54 (m, 2H), 7.24 (m, 4H),
8.39 (br s, 1 H); 13C NMR (CDCl3, 100 MHz) d 14.79,
43.00, 61.67, 104.80, 105.36, 114.73, 119.43, 119.90,
127.86, 127.91, 134.79, 135.42, 137.98, 149.95. Anal. Calcd
for C19H19N3O3$1/3H2O: C, 66.46; H, 5.77; N, 12.24.
Found: C, 66.66; H, 5.57; N, 12.14.
2.41 (s, 3H), 2.89 (m, 3H), 3.52–3.87 (m, 3H), 4.35 (m,
1H), 6.92 (m, 1H), 7.09 (m, 2H), 8.87 (br s, 1H); 13C
NMR (CDCl3, 100 MHz) d 18.6, 28.5, 33.8, 39.1, 41.5,
46.4, 80.1, 119.5, 124.5, 126.1, 126.4, 128.6, 135.7, 137.7,
155.1, 167.7. Anal. Calcd for C18H23N3O3: C, 65.63; H,
7.04; N, 12.76. Found: C, 65.23; H, 6.77; N, 12.55.
4.3.14. Rearrangement of spiro-benzimidazoline 31.
According to the general procedure, treatment of 500 mg
(1.73 mmol) of 31 with 205 mg (0.691 mmol) of triphosgene
in the presence of 1.19 g (8.64 mmol) of K2CO3 was fol-
lowed by chromatography on silica gel to afford 223 mg
(41%) of an inseparable 2.5:1 mixture of 5-(2-oxo-2,3-
dihydro-benzoimidazol-1-yl)-2,4-dihydro-2H-pyridine-1-
carboxylic acid tert-butyl ester (64) and 5-(2-oxo-2,3-dihy-
dro-benzoimidazol-1-yl)-3,6-dihydro-2H-pyridine-1-carb-
oxylic acid tert-butyl ester (65). 1H NMR (CDCl3,
400 MHz) d 1.48 (s, 9H, 65) 1.50 (s, 9H, 64), 2.07 (m, 2H,
64), 2.42 (m, 2H, 64 and 65), 3.67 (m, 2H, 64 and 65),
6.99–7.10 (m, 6H, 64 and 65); 13C NMR of 64 and 65:
4.3.12. Rearrangement of spiro-benzimidazoline 39.
According to the general procedure, treatment of 650 mg
(1.65 mmol) of 39 with 196 mg (0.661 mmol) of triphosgene
in the presence of 1.14 g (8.26 mmol) of K2CO3 was fol-
lowed by chromatography on silica gel. The first product
to elute from the column (236 mg, 34%) was identified as 4-
(5-benzoyl-2,3-dihydro-benzimidazol-1-yl)-3,6-dihydro-2H-
pyridin-1-carboxylic acid tert-butyl ester (57), which was
1
obtained as a colorless solid; mp 231–232 ꢀC. H NMR
(DMSO-d6, 400 MHz) d 1.41 (s, 9H), 2.46 (m, 2H), 3.58
(m, 2H), 4.04 (m, 2H), 5.97 (s, 1H), 7.17 (d, 1H,
J¼8.2 Hz), 7.34 (s, 1H), 7.42 (m, 1H), 7.44 (m, 2H), 7.49–