10.1002/ejoc.201900889
European Journal of Organic Chemistry
FULL PAPER
reported.[22,23] Azides 2a-2g were prepared through an adapted
Vogel’s procedure.[17] Their characterization was compared with
data reported in literature.[24-27]
120.95 (d), 131.12 (d), 136.54 (d), 137.40, 161.14, 164.45,
194.29. ESI(+)-MS: m/z [M+H]+ calcd for C11H11FN3O 220.0881,
found: 220.0877.
4-Benzoyl-5-methyl-1-(3-fluorophenyl)-1H-1,2,3-triazole (3g)
1H-NMR (CDCl3, 300 MHz): δ (ppm) 2.72 (s, 3H, CH3), 7.27-7.35
(m, 5H, Ar), 7051- 7.66 (m, 3H, Ar), 8.36-8.39 (m, 1H, Ar). 13C-
NMR (CDCl3, 75 MHz): δ (ppm) 10.66, 113.23, 113.27, 121.08,
128.33, 130.63, 131.13, 133.05, 137.31, 139.89, 143.68, 161.17,
164.48, 187.48. ESI(+)-MS: m/z [M+H]+ calcd for C16H13FN3O
282.1037, found: 282.1034.
4-Acetyl-5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazole (3h)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.70 (s, 3H, CH3), 2.77 (s,
3H, CH3), 7.70-7.79 (m, 2H, Ar), 8.44-8.53 (m, 2H, Ar). 13C NMR
(CDCl3, 75 MHz): δ (ppm) 10.42, 27.95, 125.18, 125.83, 137.32,
140.08, 144.05, 148.20,194.03. ESI(+)-MS: m/z [M+H]+ calcd for
C11H11N4O3 247.0826, found: 247.0823.
4-Benzoyl-5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazole (3i)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.77 (s, 3H, CH3), 7.50-7.60
(m, 2H, Ar), 7.61-7.68 (m, 1H, Ar), 7.74-7.84 (m, 2H, Ar), 8.33-
8.41 (m, 2H, Ar), 8.46-8.55 (m, 2H, Ar). 13C NMR (CDCl3, 75
MHz): δ (ppm) 10.82, 125.24, 125.97, 128.39, 130.62, 133.24,
137.12, 139.85, 140.29, 143.87, 148.33, 187.24. ESI(+)-MS: m/z
[M+H]+ calcd for C16H13N4O3 309.0982, found: 309.0979.
4-Acetyl-5-methyl-1-(4-chlorophenyl)-1H-1,2,3-triazole (3j)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.60 (s, 3H, CH3), 2.75 (s,
3H, CH3), 7.39-7.45 (m, 2H, Ar), 7.54-7.61 (m, 2H, Ar). 13C NMR
(CDCl3, 75 MHz): δ (ppm) 10.12, 27.86, 126.50, 129.99, 133.81,
136.24, 137.37, 143.77, 194.29. ESI(+)-MS: m/z [M+H]+ calcd for
C11H11ClN3O 236.0585, found: 236.0581.
4-Benzoyl-5-methyl-1-(4-chlorophenyl)-1H-1,2,3-triazole (3k)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.68 (s, 3H, CH3), 7.41-7.67
(m, 7H, Ar), 7.61-7.68 (m, 1H, Ar), 8.33-8.42 (m, 2H, Ar). 13C NMR
(CDCl3, 75 MHz): δ (ppm). ESI(+)-MS: m/z [M+H]+ calcd for
C16H13ClN3O 298.0742, found: 298.0738.
4-Acetyl-5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazole (3l).
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.47 (s, 3H, CH3), 2.58 (s,
3H, CH3), 2.75 (s, 3H, CH3), 7.29-7.41 (m, 4H, Ar). 13C NMR
(CDCl3, 75 MHz): δ (ppm) 10.11, 21.26, 27.82, 125.09, 130.22,
132.85, 137.41, 140.37, 143.62, 194.43. ESI(+)-MS: m/z [M+H]+
calcd for C12H14N3O 216.1131, found: 216.1127.
General Procedure for Synthesis of 1,4,5-Trisubstituted-
1,2,3-Triazoles
In a 10 ml two-necked round bottom flask, equipped with bubble
condenser and magnetic stir bar, a mixture composed by
[mpy]OTf and water 5:0.5 v/v (5 mL and 0.5 μL), freshly distilled
Et3N (2 eq), enaminone 1a-1c (1 eq) and azide 2a–2g (2 eq) were
placed. The reaction was warmed at 100 °C for the appropriate
time. The crude was extracted with dichloromethane (3 x 5 mL),
in which the [mpy]OTf is not soluble, and the combined organic
layer was evaporated under vacuum. The crude product was
purified on a flash silica gel column by using hexane/ethyl acetate
(6:4 v/v) to obtain the desired product (3a–3o). The ionic liquid,
not soluble in organic solvent was reused for successive
reactions. The configuration of regioisomers was attributed by
comparison with literature data.[12a,27]
4-Acetyl-5-methyl-1-phenyl-1H-1,2,3-triazole (3a)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.60 (s, 3H, CH3), 2.76 (s,
3H, CH3), 7.43-7.50 (m, 2H, Ar), 7.55-7.64 (m, 3H, Ar). 13C NMR
(CDCl3, 75 MHz): δ (ppm) 9.11, 26.82, 124.27, 128.67, 129.05,
134.35, 136.39, 142.67, 193.36. ESI(+)-MS: m/z [M+H]+ calcd for
C11H12N3O 202.0975, found: 202.0971.
5-Ethyl-1-phenyl-4-propionyl-1H-1,2,3-triazole (3b)
1H NMR (CDCl3, 300 MHz): δ (ppm) 1.16 (t, J=7.52 Hz, 3H, CH3),
1.26 (t, J=7.39 Hz, 3H, CH3), 2.99 (q, J=7.52 Hz, 2H, CH2), 3.26
(q, J=7.39 Hz, 2H, CH2), 7.40-7.48 (m, 2H, Ar), 7.55-7.64 (m, 3H,
Ar). 13C NMR (CDCl3, 75 MHz): δ (ppm) 7.89, 12.92, 17.14, 33.31,
125.69, 129.71, 130.21, 135.59, 142.73, 143.05, 197.18. ESI(+)-
MS: m/z [M+H]+ calcd for C13H16N3O 230.1293, found: 230.1285.
4-Benzoyl-1-benzyl-5-methyl-1H-1,2,3-triazole (3c)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.56 (s, 3H, CH3), 5.59 (s,
2H, CH2), 7.18-7.25 (m, 2H, Ar), 7.33-7.42 (m, 3H, Ar), 7.47-7.55
(m, 2H, Ar), 7.56-7.65 (m, 1H, Ar), 8.30-8.38 (m, 2H, Ar). 13C NMR
(CDCl3, 75 MHz): δ (ppm) 9.64, 51.81, 127.32, 128.23, 128.65,
129.17, 130.62, 132.84, 134.02, 137.42, 139.35, 143.86, 187.58.
ESI(+)-MS: m/z [M+H]+ calcd for C17H16N3O 278.1288, found:
278.1284.
4-Benzoyl-5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazole
(3m)
4-Benzoyl-5-methyl-1-phenyl-1H-1,2,3-triazole (3d)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.69 (s, 3H, CH3), 7.48-7.55
(m, 4H, Ar), 7.55-7.66 (m, 4H, Ar), 8.35-8.43 (m, 2H, Ar). 13C NMR
(CDCl3, 75 MHz): δ (ppm)10.64, 125.44, 128.29, 129.72, 130.09,
130.64, 132.93, 135.49, 137.45, 139.93, 143.55, 187.61.
ESI(+)-MS: m/z [M+H]+ calcd for C16H14N3O 264.1131, found:
264.1128.
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.47 (s, 3H, CH3), 2.66 (s,
3H, CH3), 7.34-7.43 (m, 4H, Ar), 7.48-7.58 (m, 2H, Ar), 7.58-7.66
(m, 1H, Ar), 8.34-8.42 (m, 2H, Ar). 13C NMR (CDCl3, 75 MHz): δ
(ppm) 10.61, 21.29, 125.23, 128.28, 130.25, 130.64, 132.89,
132.96, 137.49, 139.94, 140.39, 143.46, 187.64. ESI(+)-MS: m/z
[M+H]+ calcd for C17H16N3O 278.1288, found: 278.1284.
4-Acetyl-5-methyl-1-(4-methoxyphenyl)-1H-1,2,3-triazole (3n)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.56 (s, 3H, CH3), 2.75 (s,
3H, CH3), 3.89 (s, 3H, CH3), 7.02-7.10 (m, 2H, Ar), 7.32-7.40 (m,
2H, Ar). 13C NMR (CDCl3, 75 MHz): δ (ppm) 10.07, 27.80, 55.68,
114.80, 126.69, 128.16, 137.53, 143.55, 160.72, 194.44. ESI(+)-
MS: m/z [M+H]+ calcd for C12H14N3O2 232.1081, found: 232.1081.
4-Benzoyl-5-methyl-1-(4-methoxyphenyl)-1H-1,2,3-triazole
(3o).
4-Acetyl-1-benzyl-5-methyl-1H-1,2,3-triazole (3e)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.47 (s, 3H, CH3), 2.70 (s,
3H, CH3), 5.52 (s, 2H, CH2), 7.14-7.22 (m, 2H, Ar), 7.31-7.40 (m,
3H, Ar). 13C NMR (CDCl3, 75 MHz): δ (ppm) 9.15, 27.68, 51.70,
127.25, 128.62, 129.14, 133.97, 136.84, 144.03, 194.40. ESI(+)-
MS: m/z [M+H]+ calcd for C12H14N3O 216.1131, found: 216.1129.
4-Acetyl-5-methyl-1-(3-fluorophenyl)-1H-1,2,3-triazole (3f)
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.63 (s, 3H, CH3), 2.76 (s,
3H, CH3), 7.20-7.35 (m, 3H, Ar), 7.53-7.64 (m, 1H, Ar). 13C NMR
(CDCl3, 75 MHz): δ (ppm) 10.17, 27.89, 113.09 (d), 117.24 (d),
1H NMR (CDCl3, 300 MHz): δ (ppm) 2.65 (s, 3H, CH3), 2.91 (s,
3H, CH3), 7.04-7.14 (m, 2H, Ar), 7.37-7.46 (m, 2H, Ar), 7.49-7.58
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