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Organic & Biomolecular Chemistry
DOI: 10.1039/C5OB01345C
7.6Hz, 1H), 7.97 (d, J = 8.4 Hz, 1H), 7.88-7.84 (m, 2H), 7.77-
7.73 (m, 1H), 7.56 (t, J = 8.0 Hz, 1H), 7.51-7.45 (m, 2H), 7.21-
2-(4-(Allyloxy)phenyl)-3-nitrosoimidazo[1,2-a]pyridine (2r):
Green solid, (98%, 54 mg), mp 241-242 oC; 1H NMR (400 MHz,
7.17 (m, 1H); 13C NMR (100 MHz, CDCl3): δ 162.6, 154.,4 55 CDCl3): δ 9.85 (d, J = 5.6 Hz, 1H), 8.56 (d, J = 6.8 Hz, 2H), 7.70-
145.,3 135.9, 134.0, 133.4, 131.9, 131.4, 128.6, 128.2, 127.3,
126.3, 126.3, 126.0, 125.1, 119.7, 117.8. HRMS calcd for
C17H12N3O [M+H]+: 274.0980, found [M+H]+: 274.0963.
7.61 (m, 1H), 7.12-7.08 (m, 1H), 6.98-6.95 (m, 3H), 6.01-5.96
(m, 1H), 5.38 (d, J = 17.2 Hz, 1H), 5.24 (d, J = 10.4 Hz, 1H),
4.56-4.54 (m, 2H); 13C NMR (100 MHz, CDCl3): δ 161.7, 159.6,
151.6, 146.0, 138.8, 136.2, 132.5, 126.5, 124.2, 118.9, 118.0,
60 117.1, 115.0, 68.0. HRMS calcd for C16H14N3O2 [M+H]+:
280.1086, found [M+H]+: 280.1076.
5
2-(Naphthalen-2-yl)-3-nitrosoimidazo[1,2-a]pyridine
(2l):
Green solid, (96%, 52 mg), mp 232-233 oC; 1H NMR (400 MHz,
CDCl3): δ 10.01 (d, J = 6.4 Hz, 1H), 8.77 (d, J = 8.0 Hz, 1H),
10 8.31 (d, J = 7.2 Hz, 1H), 8.10 (d, J = 8.0 Hz, 1H), 8.09-7.90 (m,
3H), 7.69-7.57 (m, 3H), 7.38-7.35 (m, 1H); 13C NMR (100 MHz,
CDCl3): δ 162.6, 154.2, 145.3, 135.3, 134.0, 133.4, 131.8, 131.4,
3-Nitroso-2-phenylbenzo[d]imidazo[2,1-b]thiazole (4a): Green
solid, (96%, 53 mg), mp 124-125 oC; 1H NMR (400 MHz,
CDCl3): δ 8.91 (d, J = 8.4 Hz, 1H), 8.57 (d, J = 6.8 Hz, 2H), 7.69
128.5, 128.0, 127.3, 126.3, 126.2, 125.9, 125.1, 119.6, 117.7. 65 (d, J = 7.2 Hz, 1H), 7.60-7.52 (m, 4H), 7.46-7.42 (m, 1H); 13C
HRMS calcd for C17H12N3O [M+H]+: 274.0980, found [M+H]+:
NMR (100 MHz, CDCl3): δ 162.1, 158.4, 157.2, 132.7, 131.8,
131.4, 130.9, 129.9, 128.8, 126.6, 123.2, 118.8. HRMS calcd for
C15H10N3OS [M+H]+: 280.0545, found [M+H]+: 280.0539.
15 274.0963.
8-Methyl-3-nitroso-2-(pyridin-2-yl)imidazo[1,2-a]pyridine
(2m): Green solid, (98%, 46 mg), mp 212-213 oC; 1H NMR (400
2-(4-Chlorophenyl)-3-nitrosobenzo[d]imidazo[2,1-b]thiazole
1
o
MHz, CDCl3): δ 9.78 (d, J = 6.4 Hz, 1H), 8.99 (d, J = 4.4Hz, 1H), 70 (4b): Green solid, (97%, 60 mg), mp 178-179 C; H NMR (400
8.80 (d, J = 8.0 Hz, 1H), 7.96-7.91 (m, 1H), 7.70 (d, J = 7.2 Hz,
20 1H); 7.55-7.51 (m, 1H), 7.28-7.24 (m, 1H), 2.84 (s, 3H); 13C
NMR (100 MHz, CDCl3): δ 157.4, 153.9, 150.4, 149.9, 145.3,
137.0, 135.6, 128.8, 127.9, 125.3, 124.0, 120.5, 16.8. HRMS
MHz, CDCl3): δ 8.93 (d, J = 8.4 Hz, 1H), 8.54 (d, J = 8.4 Hz,
2H), 7.73 (d, J = 8.0 Hz, 1H), 7.59-7.46 (m, 4H); 13C NMR (100
MHz, CDCl3): δ 160.7, 158.4, 157.0, 138.2, 132.6, 132.0, 130.2,
130.0, 129.1, 126.8, 126.8, 123.3, 118.8. HRMS calcd for
calcd for C13H11N4O [M+H]+: 239.0933, found [M+H]+: 75 C15H9ClN3OS [M+H]+: 314.0155, found [M+H]+: 314.0149.
239.0908.
5-Methyl-3-nitroso-2-phenylbenzo[d]imidazo[2,1-b]thiazole
o
1
25 3-Nitroso-2-(thiophen-2-yl)imidazo[1,2-a]pyridine (2n): Green
solid, (96%, 44 mg), mp 201-202 oC; 1H NMR (400 MHz,
CDCl3): δ 9.88-9.85 (m, 1H), 8.47-8.46 (m, 1H), 7.83-7.76 (m,
(4c): Green solid, (96%, 56 mg), mp 124-125 C; H NMR (400
MHz, CDCl3): δ 8.78 (d, J = 8.8 Hz, 1H), 8.57 (d, J = 6.8 Hz,
2H), 7.60-7.52 (m, 4H), 7.47-7.28 (m, 1H), 2.46 (s, 3H); 13C
2H), 7.74-7.72 (m, 1H), 7.27-7.20 (m, 2H); 13C NMR (100 MHz, 80 NMR (100 MHz, CDCl3): δ 161.7, 158.1, 157.2, 137.1, 131.9,
CDCl3): δ 155.8, 151.5, 146.4, 136.5, 134.3, 133.3, 133.0, 129.2,
30 126.6, 119.3, 117.2. HRMS calcd for C11H8N3OS [M+H]+:
230.0388, found [M+H]+ : 230.0383.
131.3, 130.8, 130.6, 130.1, 128.8, 127.7, 123.1, 118.4, 21.1.
HRMS calcd for C16H12N3OS [M+H]+: 294.0701, found [M+H]+:
294.0694.
8-Methyl-3-nitroso-2-(thiophen-2-yl)imidazo[1,2-a]pyridine
o
5-Nitroso-6-phenylimidazo[2,1-b]thiazole (4d): Green solid,
o
1
1
(2o): Green solid, (97%, 47 mg), mp 219-220 C; H NMR (400 85 (98%, 45 mg), mp 147-148 C; H NMR (400 MHz, CDCl3): δ
MHz, CDCl3): δ 9.62 (d, J = 6.4 Hz, 1H), 8.37-8.36 (m, 1H),
35 7.68-7.67 (m, 1H), 7.52-7.51 (m, 1H), 7.22-7.20 (m, 1H), 7.02 (t,
J = 7.2 Hz, 1H) 2.62 (s, 3H); 13C NMR (100 MHz, CDCl3):
δ154.8, 151.5, 146.0, 135.7, 134.4, 132.7, 132.6, 128.7, 127.5,
8.57-8.54 (m, 2H), 8.32 (d, J = 4.4 Hz, 1H), 7.51-7.42 (m, 3H),
6.98 (d, J = 4.4 Hz, 1H); 13C NMR (100 MHz, CDCl3): δ159.0,
158.8, 156.8, 131.6, 131.5, 130.1, 128.9, 121.8, 116.8. HRMS
calcd for C11H8N3OS [M+H]+: 230.0388, found [M+H]+:
124.0, 119.0, 16.3. HRMS calcd for C12H10N3OS [M+H]+: 90 230.0390.
244.0544, found [M+H]+: 244.0529.
2-Phenylimidazo[1,2-a]pyridin-3-amine (6a): Gummy Mass,
40 2-Isobutyl-3-nitrosoimidazo[1,2-a]pyridine (2p): Green solid,
1
(70%, 29 mg), 1H NMR (400 MHz, CDCl3): δ 8.00-7.94 (m, 1H),
7.91-7.87 (m, 2H), 7.51 (d, J = 9.2 Hz, 1H), 7.45-7.37 (m, 2H),
7.35-7.30 (m, 1H), 7.30-7.19 (m, 1H), 7.08-7.04 (m, 1H), 6.76 (t,
95 J = 6.4 Hz, 1H), 3.42 (br, 2H); 13C NMR (100 MHz, CDCl3): δ
133.7, 132.3, 128.7, 127.3, 127.1, 123.8, 122.7, 122.5, 121.9,
117.0, 112.0. HRMS calcd for C13H12N3 [M+H]+: 210.1031,
found [M+H]+: 210.1007.
o
(95%, 38 mg), mp 142-143 C; H NMR (400 MHz, CDCl3): δ
9.78-9.76 (m, 1H), 7.75-7.73 (m, 2H), 7.21-7.18 (m, 1H), 3.35 (d,
J = 7.2 Hz, 2H), 2.47-2.37 (m, 1H), 1.02 (d, J = 6.4 Hz, 6H); 13
C
NMR (100 MHz, CDCl3): δ 155.8, 154.0, 145.9, 135.7, 126.3,
45 119.1, 117.1, 37.3, 29.3, 22.7. Anal Calcd for C11H13N3O: C,
65.01; H, 6.45; N, 20.68%; Found: C, 65.25; H, 6.26; N, 20.79%.
3-Nitrosoimidazo[1,2-a]pyridine (2q): Green solid, (97%, 28
Acknowledgments
o
1
mg), mp 120-121 C; H NMR (400 MHz, CDCl3): δ 9.65-9.63
(m, 1H), 9.21 (s, 1H), 7.84-7.76 (m, 2H), 7.29-7.24 (m, 1H); 13C
50 NMR (100 MHz, CDCl3): δ 156.4, 153.7, 146.5, 135.5, 127.2,
120.0, 118.0. HRMS calcd for C7H6N3O [M+H]+: 148.0511,
found [M+H]+ : 148.0476.
100
A.H. acknowledges the financial support from CSIR, New
Delhi (Grant No. 02(0168)/13/EMR-II). K.M. thanks CSIR
(SPMF) and M.G. thanks UGC-SRF for their fellowship.
Notes and references
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