The Journal of Organic Chemistry
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(cyclohexane/CH2Cl2 95:5) to obtain 1-(4-butylphenyl)-2-(4-
iodophenyl)diazene (2) (3.31 g, 66% yield) as an orange solid. Rf =
0.4 (cyclohexane/CH2Cl2 95:5). Mp: 84−86 °C. 1H NMR (400 MHz,
CDCl3): δ (ppm) 0.95 (t, J = 7.6 Hz, 3H, CH3), 1.38 (sex., J = 7.6 Hz,
2H, CH2), 1.65 (quin, J = 7.6 Hz, 2H, CH2), 2.69 (t, J = 7.6 Hz, 2H,
CH2), 7.32 (d, J = 8.4 Hz, 2H, CHAr), 7.63 (d, J = 8.4 Hz, 2H, CHAr),
7.83 (d, J = 8.4 Hz, 2H, CHAr), 7.85 (d, J = 8.4 Hz, 2H, CHAr). 13C
NMR (101 MHz, CDCl3): δ (ppm) 13.9 (CH3), 22.3 (CH2), 33.4
(CH2), 35.6 (CH2), 97.2 (CAr), 122.9 (2 × CHAr), 124.4 (2 × CHAr),
129.2 (2 × CHAr), 138.3 (2 × CHAr), 147.0 (CAr), 150.7 (CAr), 152.0
(CAr). ESI-MS: [M + H]+ calcd for C16H18IN2 m/z = 365.05 found m/
z = 365.00. HRMS: [M + H]+ calcd for C16H18IN2 m/z = 365.0509,
found m/z = 365.0508. UV/vis (CH3CN) (L mol−1 cm−1): λ (ε0) =
229 nm (75 800), 337 nm (60 533), 439 nm (7553).
First, acetic anhydride (75 mL) was added at 0 °C to a solution of
D-glucose (17 g, 83.26 mmol, 1 equiv) in pyridine (150 mL). After
stirring at room temperature for 2 days, the excess of acetic anhydride
was quenched with methanol. The solvent was evaporated under
vacuum. The product was precipitated in water and filtrated to obtain
1,2,3,4,6-penta-O-acetyl-D-glucopyranose (32 g, 94% yield) as a white
solid. Rf = 0.18 (cyclohexane/EtOAc 7:3).
Second, 1,2,3,4,6-penta-O-acetyl-D-glucopyranose (8 g, 20.49 mmol,
1 equiv) was dissolved in CH2Cl2 (100 mL). A solution of hydrogen
bromide (33% in acetic acid, 50 mL) was added at 0 °C. The reaction
mixture was stirred at room temperature. After 3 h the reaction was
quenched with a saturated solution of NaHCO3. The product was
extracted with CH2Cl2 (2 × 100 mL) and washed with a saturated
solution of NaHCO3 (2 × 100 mL). The organic layer was washed
with Na2SO4, filtered, and concentrated under vacuum. 2,3,4,6-Tetra-
O-acetyl-α-D-glucopyranosyl bromide (8.17 g, 97% yield) was obtained
as a colorless paste and used directly without further purification. Rf =
0.5 (cyclohexane/EtOAc 7:3).
1-(4-Butylphenyl)-2-(4-(2-(trimethylsilyl)ethynyl)-phenyl)-
diazene (3). Following the method described in the literature,21
under nitrogen atmosphere, 1-(4-butylphenyl)-2-(4-iodophenyl)-
diazene (2) (0.67 g, 1.84 mmol, 1 equiv), PdCl2(PPH3)2 (0.064 g,
0.092 mmol, 5 mol %), and copper iodide (0.024 g, 0.18 mmol, 10 mol
%) were added successively. Then, anhydrous THF (11 mL) and Et3N
(2 mL, 14.72 mmol, 8 equiv) were added to the substrates. Finally,
trimethylsilylacetylene (0.2 g, 2.02 mmol, 1.1 equiv) was added. The
reaction mixture was stirred at room temperature under nitrogen
atmosphere for 4 h. The reaction was quenched with a saturated
solution of NH4Cl. The product was extracted with CH2Cl2 (2 × 50
mL) and washed with a saturated solution of NH4Cl (100 mL). The
organic layer was dried over Na2SO4, filtered, and concentrated under
vacuum. The product was purified using column chromatography on
silica gel (cyclohexane/CH2Cl2 95:5) to obtain 1-(4-butylphenyl)-2-
(4-(2-(trimethylsilyl)ethynyl)phenyl)diazene (3) (0.58 g, 95% yield)
as an orange solid. Rf = 0.55 (cyclohexane/CH2Cl2 7:3). Mp: 78−80
°C. 1H NMR (400 MHz, CDCl3): δ (ppm) 0.28 (s, 9H, Si-CH3), 0.95
(t, J = 7.6 Hz, 3H, CH3), 1.39 (sex., J = 7.6 Hz, 2H, CH2), 1.65 (quin, J
= 7.6 Hz, 2H, CH2), 2.69 (t, J = 7.6 Hz, 2H, CH2), 7.32 (d, J = 8 Hz,
2H, CHAr), 7.60 (d, J = 8 Hz, 2H, CHAr), 7.84 (d, J = 8 Hz, 2H,
CHAr), 7.85 (d, J = 8 Hz, 2H, CHAr). 13C NMR (101 MHz, CDCl3): δ
(ppm) 0 (3 × SiCH3), 13.9 (CH3), 22.3 (CH2), 33.4 (CH2), 35.6
(CH2), 96.8 (Csp), 104.7 (Csp), 122.6 (2 × CHAr), 122.9 (2 × CHAr),
125.4 (CAr), 129.1 (2 × CHAr), 132.8 (2 × CHAr), 146.9 (CAr), 150.9
(CAr), 152.0 (CAr). ESI-MS: [M + H]+ calcd for C21H27N2Si m/z =
335.19, found m/z = 335.15. HRMS: [M + H]+ calcd for C21H27N2Si
m/z = 335.1938, found m/z = 335.1944. UV/vis (CH3CN) (L mol−1
cm−1): λ (ε0) = 229 nm (36 400), 349 nm (34 933), 442 nm (3687).
1-(4-Butylphenyl)-2-(4-ethynylphenyl)diazene (4). Following
the method described in the literature,22 to a solution of 1-(4-
butylphenyl)-2-(4-(2-(trimethylsilyl)ethynyl)phenyl)diazene (3) (0.55
g, 1.64 mmol, 1 equiv) in methanol (130 mL) was added K2CO3 (0.22
g, 1.64 mmol, 1 equiv). The reaction mixture was stirred at room
temperature for 3 h. The solvent was removed under vacuum. The
residue was diluted in CH2Cl2 (100 mL) and washed with distillated
water (2 × 100 mL) and brine (100 mL). The organic layer was dried
over Na2SO4, filtered, and concentrated under vacuum. The product
did not need further purification. 1-(4-Butylphenyl)-2-(4-
ethynylphenyl)diazene (4) (0.41 g, 95% yield) was obtained as an
orange solid. Rf = 0.47 (cyclohexane/CH2Cl2 7:3). Mp: 70−72 °C. 1H
NMR (400 MHz, CDCl3): δ (ppm) 0.97 (t, J = 7.6 Hz, 3H, CH3),
1.40 (sex., J = 7.6 Hz, 2H, CH2), 1.67 (quin, J = 7.6 Hz, 2H, CH2),
2.70 (t, J = 7.6 Hz, 2H, CH2), 3.24 (s, 1H, CH), 7.33 (d, J = 8.4 Hz,
2H, CHAr), 7.64 (d, J = 8.4 Hz, 2H, CHAr), 7.87 (d, J = 8.4 Hz, 2H,
CHAr), 7.88 (d, J = 8.4 Hz, 2H, CHAr). 13C NMR (101 MHz, CDCl3 ):
δ (ppm) 13.9 (CH3), 22.3 (CH2), 33.4 (CH2), 35.6 (CH2), 79.3 (Csp),
83.3 (Csp), 122.7 (2 × CHAr), 123.0 (2 × CHAr), 124.3 (CAr), 129.1 (2
× CHAr ), 132.9 (2 × CHAr), 147.0 (CAr), 150.8 (CAr), 152.3 (CAr).
ESI-MS: [M + H]+ calcd for C18H19N2 m/z = 263.15, found m/z =
263.10. HRMS: [M + H]+ calcd for C18H19N2 m/z = 263.1548, found
m/z = 263.1545. UV/vis (CH3CN) (L mol−1 cm−1 ): λ (ε0) = 231 nm
(26 641), 339 nm (30 358), 445 nm (2433).
Third, to a solution of 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl
bromide (6.7g, 16.29 mmol, 1 equiv) in dry CH3CN (70 mL) was
added NaN3 (3.8 g, 58.65 mmol, 3.6 equiv). The reaction mixture was
stirred at 80 °C under nitrogen atmosphere overnight. The mixture
was filtered through a Buchner apparatus and the solvent was removed
̈
under vacuum. The product 2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl
azide (5) (3.83 g, 63% yield) was obtained after recrystallization from
ethanol as white crystals. Rf = 0.31 (cyclohexane/EtOAc 7:3). 1H
NMR (400 MHz, CDCl3): δ (ppm) 2.00 (s, 3H, OCH3), 2.02 (s, 3H,
OCH3), 2.07 (s, 3H, OCH3), 2.10 (s, 3H, OCH3), 3.79 (ddd, J = 2.4,
4.8, 10 Hz, 1H, H-5), 4.16 (dd, J = 2.4, 12.4 Hz, 1H, H-6a), 4.27 (dd, J
= 4.8, 12.4 Hz, 1H, H-6b), 4.64 (d, J = 8.8 Hz, 1H, H-1), 4.95 (dd, J =
8.8, 9.6 Hz, 1H, H-2), 5.11 (dd, J = 9.2, 10 Hz, 1H, H-4), 5.21 (dd, J =
9.2, 9.6 Hz, 1H, H-3). 13C NMR (101 MHz, CDCl3): δ (ppm) 20.5 (2
× COCH3), 20.6 (COCH3), 20.7 (COCH3), 61.6 (CH2), 67.8 (CH),
70.6 (CH), 72.6 (CH), 77.0 (CH), 87.9 (CH), 169.2 (COCH3), 169.3
(COCH3), 170.1 (COCH3), 170.6 (COCH3). ESI-MS: [M + Na]+
calcd for C14H19N3NaO9 m/z = 396.10, found m/z = 396.00.
(1-((2,3,4,6-Tetra-O-acetyl)-1-β-D-glucopyranosyl)-(1,2,3-tria-
zol-4-yl))-4′-butylazobenzene (6). Following the method described
in the literature,27 to a solution of 2,3,4,6-tetra-O-acetyl-β-D-
glucopyranosyl azide (5) (2.20 g, 8.39 mmol, 1 equiv) in the
minimum amount of toluene was added 1-(4-butylphenyl)-2-(4-
ethynylphenyl)diazene (4) (3.13 g, 8.39 mmol, 1 equiv). The reaction
mixture was stirred at reflux for 24 h. The solvent was concentrated
under vacuum. The product was purified using column chromatog-
raphy on silica gel (cyclohexane/EtOAc 9:1 to 7:3) to obtain (1-
((2,3,4,6-tetra-O-acetyl)-1-β-D-glucopyranosyl)-(1,2,3-triazol-4-yl))-4′-
butylazobenzene (6) (1.68 g, 29% yield) as an orange solid. Rf = 0.22
1
(cyclohexane/EtOAc 7:3). Mp: 120−122 °C. H NMR (400 MHz,
DMSO-d6): δ (ppm) 0.92 (t, J = 7.6 Hz, 3H, CH3), 1.34 (sex., J = 7.6
Hz, 2H, CH2), 1.62 (quin, J = 7.6 Hz, 2H, CH2), 1.80 (s, 3H, OCH3),
1.97 (s, 3H, OCH3), 2.02 (s, 3H, OCH3), 2.11 (s, 3H, OCH3), 2.7 (t, J
= 7.6 Hz, 2H, CH2), 4.15−4.26 (m, 2H, H-6a,b), 4.43−4.47 (m, 1H,
H-5), 5.11 (t, J = 9.6 Hz, 1H, H-3), 5.61 (dd, J = 9.2, 9.6 Hz, 1H, H-4),
5.82 (dd, J = 9.2, 9.6 Hz, 1H, H-2), 6.32 (d, J = 9.2 Hz, 1H, H-1), 7.45
(d, J = 8.4 Hz, 2H, CHAr), 7.81 (d, J = 8.4 Hz, 2H, CHAr), 7.88 (d, J =
8.4 Hz, 2H, CHAr), 8.05 (d, J = 8.4 Hz, 2H, CHAr), 8.15 (s, 1H, CH).
13C NMR (101 MHz, DMSO-d6): δ (ppm) 13.7 (CH3), 20.1
(COCH3), 20.4 (COCH3), 20.6 (COCH3), 21.7 (CH2), 22.2
(COCH3), 32.8 (CH2), 34.7 (CH2), 61.7 (CH), 67.4 (CH), 69.2
(CH), 72.5 (CH), 73.02 (CH), 81.6 (CH), 122.8 (2 × CHAr), 123.0
(2 × CHAr), 127.8 (CAr), 129.4 (2 × CHAr), 130.0 (2 × CHAr), 133.6
(CH), 138.3 (CH), 147.2 (CAr), 150.1 (CAr), 152.3 (CAr), 168.1
(COCH3), 169.0 (COCH3), 170.0 (COCH3), 170.2 (COCH3). ESI-
MS: [M + Na]+ calcd for C32H37N5NaO9 m/z = 658.26, found m/z =
658.25. HRMS: [M + H]+ calcd for C32H38N5O9 m/z = 636.2664,
found m/z = 636.2666. UV/vis (CH3CN) (L mol−1 cm−1): λ (ε0) =
228 nm (90 767), 337 nm (42 444), 440 nm (6378).
2,3,4,6-Tetra-O-acetyl-β-D-glucopyranosyl Azide (5). Follow-
ing the method described in the literature,23 2,3,4,6-tetra-O-acetyl-β-D-
glucopyranosyl azide was obtained starting from glucose in three steps.
(1-(1-β-D-Glucopyranosyl)-(1,2,3-triazol-4-yl))-4′-butylazo-
benzene (7). Following the method described in the literature,37 to a
solution of (1-((2,3,4,6-tetra-O-acetyl)-1-β-D-glucopyranosyl)-(1,2,3-
9558
dx.doi.org/10.1021/jo301466w | J. Org. Chem. 2012, 77, 9553−9561