Synlett 2009(18): 2977-2981  
DOI: 10.1055/s-0029-1218267
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

One-Pot Synthesis of 1,4-Disubstituted 1,2,3-Triazoles from Aldehydes and Amines

Stéphane Maisonneuve, Juan Xie*
PPSM, Institut d’Alembert, ENS de Cachan, CNRS UMR 8531, 61 Avenue du Président Wilson, 94235 Cachan, France
Fax: +33(1)47405586; e-Mail: joanne.xie@ens-cachan.fr;
Further Information

Publication History

Received 17 July 2009
Publication Date:
08 October 2009 (online)

Abstract

A one-pot, three-step synthesis of 1,4-disubstituted 1,2,3-triazoles from aldehyde and amine has been developed by in situ transformation of aldehyde into alkyne, followed by diazo-transfer of amine into azide and subsequent cycloaddition. This procedure allowed the synthesis of fluorescent amino acid derivatives as well as glycoconjugate mimetics.

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General Procedure
To a solution of aldehyde (1 equiv) in a mixture MeOH-CH2Cl2 (4 mL/4 mL for 0.5 mmol of aldehyde) were added K2CO3 (4 equiv) and the Bestmann-Ohira reagent (1.8 equiv). The mixture was stirred at r.t. until complete conversion of aldehyde to alkyne (TLC monitoring -
6 h maximum). Amine hydrochloride salt (1.2 equiv), CuSO5˙5H2O (1.2 equiv) and the imidazole-1-sulfonyl azide (1.2 equiv) were then added to the reaction mixture and stirred at r.t. to transform the amine into the azide intermediate. Reaction was judged to be complete when imidazole-1-sulfonyl azide spot disappeared on TLC (4 h maximum). Finally, ascorbic acid (4 equiv) was added, and the reaction was stirred at r.t. overnight. The mixture was filtered through a pad of Celite, washed with MeOH, and the solvents evaporated under vacuum. The residue was purified by column chromatography on silica gel (40-63 µM) to afford the triazoyl compound.
Analytical Data for Selected Compounds Compound 12: mp 191 ˚C; R f  = 0.55 (EtOAc-cyclohexane = 1:1); [α]D -89.2 (c 0.48, CH2Cl2). ¹H NMR (400 MHz, CDCl3): δ = 3.89 (s, 3 H), 5.37 (s, 2 H, CH2), 8.01-8.29 (m, 9 H), 8.67 (d, 1 H, J = 9.2 Hz). ¹³C NMR (100 MHz, CDCl3): δ = 51.0 (CH2), 53.3 (CH3), 124.3, 124.7, 125.0, 125.3, 126.2, 127.3, 127.5, 128.0, 128.4, 128.7 (CH), 131.0, 131.4, 131.5, 148.0, 166.9 (C). ESI-HRMS: m/z calcd for C21H15N3NaO2: 364.1062; found: 364.1057.
Compound 29: mp 114 ˚C; R f  = 0.48 (EtOAc); [α]D -35.2 (c 0.47, CH2Cl2). ¹H NMR (400 MHz, CDCl3): δ = 1.31 (s, 3 H), 1.36 (s, 3 H), 1.45 (s, 3 H), 1.60 (s, 3 H), 1.83 (s, 3 H), 1.83-2.01 (m, 2 H), 3.52-3.53 (m, 1 H), 3.61-3.63 (m, 1 H), 3.67 (dd, 1 H, J = 6.4, 10.1 Hz), 3.90 (dd, 1 H, J = 7.4, 10.1 Hz), 3.95-3.97 (m, 1 H), 4.11-4.13 (m, 1 H), 4.25 (t, 1 H, J = 6.8 Hz), 4.37 (dd, 1 H, J = 2.8, 5.0 Hz), 4.39-4.51 (m, 6 H), 4.55-4.59 (m, 3 H), 4.70 (dd, 1 H, J = 2.3, 7.8 Hz), 5.19 (d, 1 H, J = 1.8 Hz), 5.60 (d, 1 H, J = 5.0 Hz), 6.60 (d, 1 H, J = 9.6 Hz), 7.20-7.33 (m, 15 H), 7.65 (s, 1 H). ¹³C NMR (100 MHz, CDCl3): δ = 23.4, 24.3, 25.1, 26.1, 26.3 (CH3), 32.4, 46.9 (CH2), 47.8, 64.7, 65.3 (CH); 67.6 (CH2), 70.8, 70.9 (CH); 72.0, 72.3 (CH2), 72.7, 73.2 (CH), 73.4 (CH2), 74.2, 75.1, 77.3 (CH), 96.7 (CH), 109.0, 109.3 (C), 123.6, 127.8, 127.9, 128.6, 128.7 (CH), 137.3, 137.5, 138.2, 145.1, 170.0 (C). ESI-HRMS: m/z calcd for C44H54N4NaO10: 821.3738; found: 821.3732.