Synlett 2007(19): 3003-3006  
DOI: 10.1055/s-2007-992357
LETTER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Some Novel 1,2,3-Triazole-Fused Oligonucleoside and Oligosaccharide Analogues

Pei-Yuan Jina, Peng Jina, Yi-An Ruana, Yong Ju*a,b, Yu-Fen Zhaoa
a Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, P. R. of China
b State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. of China
Fax: +86(10)62781695; e-Mail: juyong@tsinghua.edu.cn;
Further Information

Publication History

Received 27 July 2007
Publication Date:
08 November 2007 (online)

Abstract

Several 1,2,3-triazole-fused oligonucleoside and oligosaccharide analogues were synthesized by involving a Cu(I)-catalyzed 1,3-dipolar cycloaddition as the key step. The structures of the products were confirmed on the basis of the 1H NMR and ESI-MS methods.

15

Typical Procedure for the Preparation of 4: 1,2-Ethylene-diamine (120 mg, 2 mmol) was dissolved in MeCN (10 mL). Crushed KOH (493 mg, 8.8 mmol) was added and after 15 min of stirring an 80% propargyl bromide solution in toluene (0.76 mL, 8.8 mmol) was slowly added via syringe. The mixture was stirred for 6 h. The reaction mixture was reduced to a brown oil to which ice-water (15 mL) was added and the mixture was subsequently extracted with CH2Cl2 (3 × 15 mL). The combined extracts were washed with H2O, dried over anhyd MgSO4, filtered, and reduced to a brown syrup. Flash column chromatography using hexanes-EtOAc (20:1) yielded the alkyne 4 (339 mg, 80%) as a pale yellow. 1H NMR (300 MHz, CDCl3): δ = 3.48 (d, J = 2.4 Hz, 8 H, 4 × CH2), 2.72 (s, 4 H, 2 × CH2), 2.22 (t, J = 2.4 Hz, 4 H, 4 × CH). ESI-MS (+): m/z = 213 [M + H]+, 235 [M + Na]+.
Compound 5: ESI-MS (+): m/z = 227 [M + H]+, 249 [M + Na]+, 265 [M + K]+.
Compound 6: ESI-MS (+): m/z = 269 [M + H]+, 307 [M + K]+.
Compound 12: ESI-MS (+): m/z = 294 [M + H]+, 316 [M + Na]+, 332 [M + K]+.
Compound 13: ESI-MS: m/z = 321 [M + H]+, 360 [M + K]+.

16

Typical Procedure for the Preparation of 7a: Triazole 7a was prepared from azide a (0.4 mmol) and alkyne 4 (21 mg, 0.1 mmol) with CuSO4 (5 mg, 5% equiv of azide) and sodium ascorbate (8 mg, 10% equiv of azide) in THF-H2O (1:1, 10 mL) at r.t. for 12 h. Then the solvent was removed and the residue was purified by column chromatography over silica gel using CH2Cl2-MeOH (4:1) as eluent; white solid; yield: 42%; mp 246-249 °C. 1H NMR (300 MHz, DMSO-d 6): δ = 8.28 (s, 4 H, triazole-H), 7.82 (s, 4 H, H-6), 7.70 (m, 4 H, H-3), 6.43 (t, J = 6.0 Hz, 4 H, H-1′), 5.36 (m, 4 H, H-3′), 4.21 (m, 4 H, H-4′), 3.68 (m, 8 H, 4 × CH2), 3.59-3.63 (m, 8 H, H-5′), 2.59-2.74 (m, 12 H, H-2′, NCH2), 1.81 (s, 12 H, Me-5). ESI-MS (+): m/z = 1281 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C54H69N22O16: 1281.5256; found: 1281.5269.
Compound 7b: white solid; yield: 60%; mp 198-201 °C. 1H NMR (300 MHz, CDCl3): δ = 7.98-8.19 (m, 4 H, triazole-H), 5.90-5.98 (m, 4 H, H-1), 5.25-5.65 (m, 12 H, H-2, H-3, H-4), 4.02-4.30 (m, 12 H, H-5, H-6), 3.73-3.87 (br, 8 H), 2.60-2.86 (br, 4 H), 1.83-2.06 (m, 48 H, 16 × COMe). ESI-MS (+): m/z = 1705 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C70H93N14O36: 1705.5871; found: 1705.5857.
Compound 8a: yield: 38%; mp 253-255 °C. ESI-MS (+): m/z = 1295 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C55H71N22O16: 1295.5413; found: 1295.5436.
Compound 8b: yield: 65%; mp 190-195 °C. ESI-MS (+): m/z = 1719 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C71H95N14O36: 1719.6028; found: 1719.6008.
Compound 9a: yield: 41%; mp 257-260 °C. ESI-MS (+): m/z = 1359 [M + Na]+. HRMS (ESI): m/z [M + Na]+ calcd for C58H76N22NaO16: 1359.5702; found: 1359.5702.
Compound 9b: yield: 51%; mp 190-193 °C. ESI-MS (+): m/z = 1761 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C74H101N14O36: 1761.6497; found: 1761.6482.
Compound 14a: yield: 48%; mp 270-273 °C. ESI-MS (+): m/z = 1651 [M + Na]+. HRMS (ESI): m/z [M + Na]+ calcd for C69H88N28NaO20: 1651.6622; found: 1651.6630.
Compound 14b: yield: 70%; mp 206-211 °C. ESI-MS (+): m/z = 2159 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C89H119N18O45: 2159.7571; found: 2159.7588.
Compound 15a: yield: 39%; mp 266-269 °C. ESI-MS (+): m/z = 1657 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C71H93N28O20: 1657.7115; found: 1657.7117.
Compound 15b: yield: 63%; mp 211-216 °C. ESI-MS (+): m/z = 2187 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C91H123N18O45: 2187.7884; found: 2187.7838.

18

Typical Procedure for the Preparation of 18: Amine 16 (472 mg, 1 mmol) was dissolved in MeCN (10 mL). Crushed K2CO3 (304 mg, 2.2 mmol) was added and after 15 min of stirring an 80% propargyl bromide solution in toluene (0.19 mL, 2.2 mmol) was slowly added via syringe. The mixture was allowed to stir overnight and until TLC analysis revealed the reaction to be complete. The reaction mixture was reduced to a brown oil to which ice-water (15 mL) was added and the mixture was subsequently extracted with CH2Cl2 (3 × 15 mL). The combined extracts were washed with H2O, dried over anhyd MgSO4, filtered, and reduced to a brown syrup. Flash column chromatography using CH2Cl2-MeOH (80:1) yielded the alkyne 18 (389 mg, 71%) as a pale yellow; mp 122-125 °C. 1H NMR (300 MHz, CDCl3): δ = 5.36 (m, 1 H, H-6′′), 5.05 (br, 1 H, CONH), 4.49 (m, 1 H, H-3′′), 3.44 (d, J = 2.4 Hz, 4 H, NCH2), 3.27 (q, J = 5.7 Hz, 2 H, NHCH2), 2.69 (t, J = 5.7 Hz, 2 H, NCH2), 2.32 (br, 2 H, H-7′′), 2.23 (t, J = 2.4 Hz, 2 H), 1.01-2.02 (br, 26 H, other protons of steroidal moiety), 1.00 (s, 3 H, Me-19′′), 0.90 (d, J = 6.5 Hz, 3 H, Me-21′′), 0.86 (m, 6 H, Me-26′′, Me-27′′), 0.67 (s, 3 H, Me-18′′). ESI-MS (+): m/z = 549 [M + H]+, 571 [M + Na]+, 587 [M + K]+. HRMS (ESI): m/z [M + H]+ calcd for C36H57N2O2: 549.4415; found: 549.4422.
Compound 19: mp 124-127 °C. ESI-MS (+): m/z = 605 [M + H]+, 627 [M + Na]+, 643 [M + K]+. HRMS (ESI): m/z [M + H]+ calcd for C40H65N2O2: 605.5041; found: 605.5041.
Compound 24: mp 114-117 °C. ESI-MS (+): m/z = 630 [M + H]+, 652 [M + Na]+. HRMS (ESI): m/z [M + H]+ calcd for C41H64N3O2: 630.4993; found: 630.4999.
Compound 25: mp 125-129 °C. ESI-MS (+): m/z = 658 [M + H]+, 680 [M + Na]+. HRMS (ESI): m/z [M + H]+ calcd for C41H68N3O2: 658.5306; found: 658.5310.

19

Typical Procedure for the Preparation of 20a: Triazole 20a was prepared by heating azide a (53 mg, 0.2 mmol) and alkyne 18 (55 mg, 0.1 mmol) with CuSO4 (2.5 mg, 5% equiv of azide) and sodium ascorbate (4 mg, 10% equiv of azide) in THF-H2O (1:1, 10 mL) at 50 °C for 12 h. Then the solvent was removed and the residue was purified by column chromatography over silica gel using CH2Cl2-MeOH (7:1) as eluent; white solid; yield: 46%; mp 301-305 °C. 1H NMR (300 MHz, DMSO-d 6): δ = 11.33 (br, 2 H, H-3), 8.31 (s, 2 H, triazole-H), 7.89 (s, 2 H, H-6), 6.44 (t, J = 6.5 Hz, 2 H, H-1′), 5.47 (m, 2 H, H-3′), 5.32 (m, 1 H, H-6′′), 4.58 (br, 1 H, CONH), 4.51 (m, 1 H, H-3′′), 3.58-3.75 (m, 6 H, H-4′, H-5′), 3.37 (s, 4 H, NCH2), 3.16 (m, 2 H, NHCH2), 2.54-2.80 (m, 6 H, H-2′, NCH2), 2.34 (br, 2 H, H-7′′), 1.83 (s, 6 H, Me-5), 0.97-1.99 (br, 26 H, other protons of steroidal moiety), 0.96 (s, 3 H, Me-19′′), 0.87 (d, J = 6.5 Hz, 3 H, Me-21′′), 0.84 (m, 6 H, Me-26′′, Me-27′′), 0.66 (s, 3 H, Me-18′′). ESI-MS (+): m/z = 1083 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C56H83N12O10: 1083.6350; found: 1083.6373.
Compound 20b: white solid; yield: 65%; mp 220-223 °C. 1H NMR (300 MHz, CDCl3): δ = 7.88 (s, 2 H, triazole-H), 5.85 (t, J = 4.2, 4.8 Hz, 2 H, H-1′), 5.30-5.55 (m, 4 H, H-2′, H-3′), 5.25 (m, 1 H, H-6′′), 4.53 (br, 1 H, CONH), 4.51 (m, 1 H, H-3′′), 4.00-4.27 (m, 8 H, H-4′, H-5′, H-6′), 3.73 (s, 4 H, NCH2), 3.23 (m, 2 H, NHCH2), 2.61 (m, 2 H, NCH2), 2.34 (br, 2 H, H-7′′), 2.02-2.09 (s, 24 H, 8 × COMe), 0.96-1.99 (br, 26 H, other protons of steroidal moiety), 1.09 (s, 3 H, Me-19′′), 0.95 (d, J = 6.5 Hz, 3 H, Me-21′′), 0.85 (m, 6 H, Me-26′′, Me-27′′), 0.67 (s, 3 H, Me-18′′). ESI-MS (+): m/z = 1295 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C64H95N8O20: 1295.6657; found: 1295.6638.
Compound 21a: yield: 51%; mp 286-290 °C. ESI-MS (+): m/z = 1139 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C60H91N12O10: 1139.6976; found: 1139.6960.
Compound 21b: yield: 58%; mp 215-218 °C. ESI-MS (+): m/z = 1351 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C68H103N8O20: 1351.7283; found: 1351.7267.
Compound 26a: yield: 36%; mp 307-310 °C. ESI-MS (+): m/z = 1431 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C71H103N18O14: 1431.7896; found: 1431.7893.
Compound 26b: yield: 59%; mp 222-227 °C. ESI-MS (+): m/z = 1749 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C83H121N12O29: 1749.8357; found: 1749.8346.
Compound 27a: yield: 45%; mp 311-314 °C. ESI-MS (+): m/z = 1459 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C73H107N18O14: 1459.8209; found: 1459.8216.
Compound 27b: yield: 55%; mp 229-232 °C. ESI-MS (+): m/z = 1777 [M + H]+. HRMS (ESI): m/z [M + H]+ calcd for C85H125N12O29: 1777.8670; found: 1777.8680.