M. Kato et al. / Bioorg. Med. Chem. 13 (2005) 1563–1571
1569
66.12 (C-6), 14.82 (CH3); FABHRMS Calcd for
C8H15N2O4 (MH+) 203.1033, found 203.1023.
Pakꢂ Cartridge (Waters). Lyophilization of the pass-
through fractions gave the oxazoline 4 as colorless pow-
der (494 mg, 63%). H NMR (300 MHz, CD3OD) dH
1
4.1.3.
N1-(2-Acetamido-2-deoxy-b-D-glucopyranosyl)-
5.74 (d, 1H, J = 7.5 Hz, H-1), 4.37 (dd, 1H, J = 7.5
and 5.1 Hz, H-2), 3.76 (dd, 1H, J = 12.0and 3.0Hz,
H-6a), 3.71 (dd, 1H, J = 6.6 and 5.1 Hz, H-3), 3.70
(dd, 1H, J = 12.0and 5.1 Hz, H-6b), 3.48 (dd, 1H,
J = 8.7 and 6.6 Hz, H-4), 3.29 (ddd, 1H, J = 8.7, 5.1
and 3.0Hz, H-5), 2.05 (d, 3H, J = 0.9 Hz, CH3); 13C
NMR (75 MHz, CD3OD) dC 171.1 (C@N), 93.48 (C-
1), 82.36 (C-4), 75.38 (C-3), 74.77 (C-2), 69.52 (C-5),
63.06 (C-6), 14.11 (CH3); FABHRMS Calcd for
C8H14NO5 (MH+) 204.0872, found 204.0874.
phenylacetamidine hydrobromide (3). 2-Acetamido-
2-deoxy-b-D-glucopyranosylamine (7) was prepared
from N-acetyl-D-glucosamine according to a modified
procedure of our previous method.22 N-Acetyl-D-gluco-
samine (22.1 g, 0.1 mol) and ammonium bicarbonate
(7.91 g, 0.1 mol) were added to MeOH (100 mL) satu-
rated with ammonia gas at 0 ꢁC in a pressure bottle.
The bottle was tightly closed, and the mixture was stir-
red at 40 ꢁC for 3 days. The suspension became a solu-
tion in 6 h, and colorless precipitate was then formed
in 12 h. Ethanol (150mL) was added to the reaction
mixture, and the mixture was kept at 4 ꢁC to precipitate
out the product. The crystalline precipitate was collected
by filtration and washed with EtOH and ether, succes-
sively, to give a mixture of 7 and its carbamate (1:0.8,
1H NMR in D2O) (20.6 g). The crude product was dis-
solved in MeOH (500 mL) and was evaporated to dry-
ness to decompose the carbamate. Evaporation was
repeated for three times to give pure glycosylamine 7
4.1.5. 2-Methyl-4-(10,20,30,40-tetrahydroxybutyl)imidaz-
ole (6) from compound 5. To a solution of 5 (1.95 g,
4.73 mmol) in dry MeOH (50mL) was added 1 M so-
dium methoxide (0.24 mL, 0.24 mmol) at room temper-
ature. The mixture was stirred at room temperature for
38 h. After the reaction was complete (TLC, n-BuOH/
AcOH/H2O 3:1:2, anisaldehyde), the reaction mixture
was concentrated to dryness. The residue was crystal-
lized from MeOH to afford the imidazolosugar 6 (free
base) as colorless powder (315 mg, 33%). 1H NMR
(400 MHz, D2O) dH 6.97 (s, 1H, H-5), 4.84 (d, 1H,
J = 4.4 Hz, H-10), 3.82 (dd, 1H, J = 6.8 and 4.4 Hz, H-
20), 3.76 (dd, 1H, J = 11.6 and 3.2 Hz, H-40a), 3.68 (dt,
1H, J = 6.8 and 3.2 Hz, H-30), 3.59 (dd, 1H, J = 11.6
and 6.8 Hz, H-40b), 2.33 (s, 3H, CH3); 13C NMR
(100 MHz, D2O) dC 148.7 (C-2), 139.8 (C-4), 118.9 (C-
1
as colorless glassy hygroscopic foam (17.2 g, 78%). H
NMR (300 MHz, D2O) dH 4.14 (d, 1H, J = 9.0Hz, H-
1), 3.88 (dd, 1H, J = 12.2 and 2.0Hz, H-6a), 3.70(dd,
1H, J = 12.3 and 5.6 Hz, H-6b), 3.61 (dd, 1H, J = 9.8
and 9.2 Hz, H-4), 3.51 (m, 1H, H-2), 3.4 (m, 2H, H-3
and H-5), 2.04 (s, 3H, CH3CO). The glycosylamine 7
(560mg, 2.54 mmol) suspended in dry pyridine
(10mL) was cooled to 0 ꢁC. S-Methyl phenylthioacet-
imidate hydrobromide (prepared from phenylthioaceta-
mide and bromomethane in acetone, 100%) (630 mg,
2.56 mmol) was added to the suspension. The mixture
was stirred at 0 ꢁC for 5 h under an argon atmosphere,
during which the glycosylamine 7 was dissolved to give
a clean solution. The reaction mixture was evaporated,
and the crude product dissolved in water was applied
to a medium-pressure ODS column. The column was
eluted with a linear gradient of MeOH (0to 50%) in
water and the fractions absorbing at 254 nm were col-
0
5), 76.59 (C-20), 74.10(C-3 ), 69.62 (C-10), 65.28 (C-40),
15.15 (CH3). The imidazolosugar 6 (0.21 g, 1.04 mmol)
was treated with 12 M HCl (0.095 mL, 1.14 mmol) and
was lyophilized to afford the hydrochloride salt of 6 as
23
D
colorless powder (0.25 g). mp 158.0–160.8 ꢁC; ½a
ꢀ14.0ꢁ (c 0.2, H2O); UV (H2O), kmax 210nm ( e 5100);
IR (KBr) mmax 3180 (br), 1640, 1560, 1340, 1300, 1270,
1210, 1120, 1090, 1050, 950, 890, 780, 750, 620 and
500 cmꢀ1 ; H NMR (400 MHz, D2O) dH 7.23 (d, 1H,
1
J = 0.8 Hz, H-5), 5.11 (dd, 1H, J = 2.4 and 0.8 Hz, H-
10), 3.85 (dd, 1H, J = 11.6 and 2.8 Hz, H-40a), 3.79
(ddd, 1H, J = 8.4, 5.6 and 2.8 Hz, H-30), 3.70(dd, 1H,
J = 8.4 and 2.4 Hz, H-20), 3.67 (dd, 1H, J = 11.6 and
5.6 Hz, H-40b), 2.59 (s, 3H, CH3); 13C NMR
(100 MHz, D2O) dC 147.3 (C-2), 135.7 (C-4), 117.8 (C-
lected and freeze-dried to afford 3 as colorless and
25
hygroscopic powder (473 mg, 45%). ½a ꢀ10.8ꢁ (c 1.0,
H2O); 1H NMR (300 MHz, D2O) dHD 7.46–7.30(m,
5H, aromatic), 4.93 (d, 1H, J = 9.3 Hz, H-1), 3.95–3.72
(m, 5H), 3.63–3.45 (m, 3H), 1.78 (s, 3H, CH3); 13C
NMR (75 MHz, D2O) dC 177.6 (C@O), 171.5 (C@N),
134.7, 132.2, 131.7, 131.2 (aromatic), 83.30(C-1),
80.45 (C-5), 76.10 (C-3), 71.89 (C-4), 63.03 (C-6) 56.59
(C-2), 41.48 (CH2Ph), 24.61 (CH3CO); Anal. Calcd
for C16H24BrN3O5Æ1.4H2O: C, 43.33; H, 6.09; N,
9.47. Found: C, 43.33; H, 5.89; N, 9.56; FABHRMS
Calcd for C16H24N3O5 (MH+) 338.1717, found
338.1711.
0
5), 75.55 (C-20), 73.40(C-3 ), 66.96 (C-10), 65.52 (C-40),
13.30(CH ); Anal. Calcd for C8H15ClN2O4: C, 40.26;
3
H, 6.33; N, 11.74. Found: C, 40.03; H, 6.36; N, 11.49;
FABHRMS Calcd for C8H15N2O4 (MH+) 203.1033,
found 203.1027.
4.2. Compound 6 from D-glucosamine
D-Glucosamine hydrochloride (5.04 g, 23.4 mmol) was
dissolved in 1 M carbonate buffer (pH 10) (140 mL).
Ethyl acetimidate hydrochloride (4.33 g, 35.0mmol)
was added portionwise to the solution, and the mixture
was stirred for 5 h at room temperature. Another por-
tion of ethyl acetimidate hydrochloride (1.53 g,
12.4 mmol) was added. After 2 h, another portion of
ethyl acetimidate hydrochloride (3.14 g, 25.4 mmol)
was added, and the mixture was stirred for further 2 h
4.1.4.
2-Methyl-(1,2-dideoxy-a-D-glucopyrano)[2,1-d]-
oxazoline (4). The peracetylated oxazoline 927(1.02 g,
3.10mmol) prepared from 2,3,4,6-tetra- O-acetyl-b-D-
glucopyranosyl azide (8) was dissolved in MeOH
(10mL) containing triethylamine (2 mL). The mixture
was stirred for 15 h at room temperature and was con-
centrated in vacuo. The residue was dissolved in cold
water (2 mL) and was passed through an ODS Sep-