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N-cyclohexyl-1,3-benzothiazol-2-amine (3d).9b Following the
general procedure and purication: petroleum ether–AcOEt:
(8 : 2, v/v), 3d was obtained as a grey solid (159 mg, 68%). Mp:
108–109 ꢀC (litt 109–110 ꢀC); 1H NMR (400 MHz, CDCl3) d 7.57
(d, J ¼ 7.8 Hz, 1H), 7.52 (d, J ¼ 8.1 Hz, 1H), 7.30–7.24 (m, 1H),
7.06 (t, J ¼ 7.6 Hz, 1H), 5.26 (bs, 1H, NH), 3.65–3.51 (m, 1H),
2.19–2.07 (m, 2H), 1.82–1.72 (m, 2H), 1.70–1.59 (m, 1H), 1.51–
1.22 (m, 5H); 13C NMR (101 MHz, CDCl3) d 166.5 (C), 152.6 (C),
130.4 (C), 125.9 (CH), 121.3 (CH), 120.7 (CH), 118.8 (CH), 54.4
(CH), 33.3 (CH2), 25.5 (CH2), 24.7 (CH2).
N-butyl-1,3-benzothiazol-2-amine (3e).9b Following the
general procedure and purication: petroleum ether–AcOEt:
(8 : 2, v/v), 3e was obtained as a white solid (148 mg, 72%). Mp:
84–85 ꢀC (litt 83–84 ꢀC); 1H NMR (400 MHz, CDCl3) d 7.59 (d, J ¼
7.9 Hz, 1H), 7.53 (d, J ¼ 8.1 Hz, 1H), 7.33–7.25 (m, 1H), 7.08 (t, J
¼ 7.5 Hz, 1H), 5.41 (bs, 1H, NH), 3.43 (t, J ¼ 7.0 Hz, 2H), 1.68 (p, J
¼ 7.1 Hz, 2H), 1.46 (h, J ¼ 7.3 Hz, 2H), 0.98 (t, J ¼ 7.3 Hz, 3H);
13C NMR (101 MHz, CDCl3) d 167.6 (C), 152.6 (C), 130.4 (C),
125.9 (CH), 121.4 (CH), 120.8 (CH), 118.8 (CH), 45.4 (CH2), 31.6
(CH2), 20.0 (CH2), 13.7 (CH3).
N-benzyl-1,3-benzothiazol-2-amine (3f).17 Following the
general procedure and purication: petroleum ether–AcOEt:
(8 : 2, v/v), 3f was obtained as a beige solid (169 mg, 70%). Mp:
161–162 ꢀC (litt 160–161 ꢀC); 1H NMR (400 MHz, CDCl3) d 7.58
(d, J ¼ 8.0 Hz, 1H), 7.55 (d, J ¼ 8.2 Hz, 1H), 7.43–7.27 (m, 6H),
7.10 (t, J ¼ 7.5 Hz, 1H), 5.60 (s, 1H, NH), 4.65 (s, 2H); 13C NMR
(101 MHz, CDCl3) d 167.1 (C), 152.4 (C), 137.4 (C), 130.6 (C),
128.8 (CH), 127.9 (CH), 127.7 (CH), 126.0 (CH), 121.8 (CH), 120.8
(CH), 119.1 (CH), 49.4 (CH2).
N-phenyl-1,3-benzothiazol-2-amine (3g).6b Following the
general procedure and purication: petroleum ether–AcOEt:
(8 : 2, v/v), 3g was obtained as a white solid (139 mg, 61%). Mp:
156–157 ꢀC (litt 157–159 ꢀC); 1H NMR (400 MHz, CDCl3) d 8.76
(s, 1H, NH), 7.65 (d, J ¼ 7.8 Hz, 1H), 7.60 (d, J ¼ 8.0 Hz, 1H), 7.52
(d, J ¼ 7.8 Hz, 2H), 7.42 (t, J ¼ 7.8 Hz, 2H), 7.34 (t, J ¼ 7.7 Hz,
1H), 7.21–7.14 (m, 2H); 13C NMR (101 MHz, chloroform-d)
d 164.7 (C), 151.4 (C), 139.9 (C), 129.9 (C), 129.6 (CH), 126.1
(CH), 124.4 (CH), 122.4 (CH), 120.9 (CH), 120.3 (CH), 119.4 (CH).
N-(4-methoxyphenyl)-1,3-benzothiazol-2-amine (3h).6b Follow-
ing the general procedure and purication: petroleum ether–
AcOEt: (8 : 2, v/v), 3h was obtained as a beige solid (157 mg,
61%). Mp: 160–161 ꢀC (litt 161–162 ꢀC); 1H NMR (400 MHz,
CDCl3) d 8.25 (bs, 1H, NH), 7.58 (d, J ¼ 7.8 Hz, 1H), 7.51 (d, J ¼
8.0 Hz, 1H), 7.41 (d, J ¼ 8.4 Hz, 2H), 7.30 (t, J ¼ 7.7 Hz, 1H), 7.11
(t, J ¼ 7.5 Hz, 1H), 6.96 (d, J ¼ 8.4 Hz, 2H), 3.84 (s, 3H); 13C NMR
(101 MHz, chloroform-d) d 166.5 (C), 157.3 (C), 151.9 (C), 132.9
(C), 130.1 (C), 126.0 (CH), 123.9 (CH), 122.1 (CH), 120.8 (CH),
119.1 (CH), 114.8 (CH), 55.6 (CH3).
130.0 (C), 125.9 (CH), 122.5 (CH), 121.1 (CH), 119.6 (CH), 119.4
(CH), 113.3 (C).
Methyl 4-[(1,3-benzothiazol-2-yl)amino]benzoate (3j).19 Follow-
ing the general procedure and purication: petroleum ether–
AcOEt: (8 : 2, v/v), 3j was obtained as a grey solid (235 mg, 83%).
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Mp: 209–210 ꢀC (degradation); (litt 204–206 ꢀC); H NMR (400
MHz, DMSO-d6) d 10.90 (bs, 1H, NH), 7.98 (d, J ¼ 8.9 Hz, 2H), 7.92
(d, J ¼ 8.9 Hz, 2H), 7.88 (d, J ¼ 7.9 Hz, 1H), 7.69 (d, J ¼ 7.9 Hz, 1H),
7.38 (td, J ¼ 7.7, 1.3 Hz, 1H), 7.22 (td, J ¼ 7.6, 1.2 Hz, 1H), 3.84 (s,
3H); 13C NMR (101 MHz, DMSO-d6) d 165.9 (C), 161.0 (C), 151.7
(C), 144.7 (C), 130.6 (CH), 130.2 (C), 126.0 (CH), 122.8 (CH), 122.5
(C), 121.2 (CH), 119.7 (CH), 117.0 (CH), 51.8 (CH3).
1-{4-[(1.3-benzothiazol-2-yl)amino]phenyl}ethan-1-one (3k).18
Following the general procedure and purication: petroleum
ether–AcOEt: (8 : 2, v/v), 3k was obtained as a yellow solid (172
mg, 65%). Mp: 190–191 ꢀC; (litt 189–190 ꢀC); 1H NMR (400 MHz,
CDCl3) d 8.05 (bs, 1H, NH), 8.01 (d, J ¼ 8.7 Hz, 2H), 7.71 (dd, J ¼
11.1, 8.0 Hz, 2H), 7.66 (d, J ¼ 8.7 Hz, 2H), 7.40 (ddd, J ¼ 8.3, 7.4,
1.3 Hz, 1H), 7.27 (td, J ¼ 7.3, 1.2 Hz, 1H), 2.60 (s, 3H); 13C NMR
(101 MHz, CDCl3) d 196.8 (C), 161.5 (C), 151.5 (C), 144.1 (C),
132.1 (C), 130.5 (C), 130.4 (CH), 126.6 (CH), 123.5 (CH), 121.1
(CH), 120.5 (CH), 117.6 (CH), 26.6 (CH3).
N-(2-methylphenyl)-1,3-benzothiazol-2-amine (3l).17 Follow-
ing the general procedure and purication: petroleum ether–
AcOEt: (8 : 2, v/v), 3l was obtained as a brown solid (101 mg,
42%). Mp: 129–130 ꢀC (litt 127–128 ꢀC); 1H NMR (400 MHz,
CDCl3) d 8.00 (bs, 1H, NH), 7.67 (d, J ¼ 8.0 Hz, 1H), 7.58 (d, J ¼
7.9 Hz, 1H), 7.54–7.45 (t, J ¼ 7.0 Hz, 1H), 7.34–7.27 (m, 3H), 7.20
(t, J ¼ 7.5 Hz, 1H), 7.12 (t, J ¼ 7.6 Hz, 1H), 2.36 (s, 3H); 13C NMR
(101 MHz, CDCl3) d 166.4 (C), 151.8 (C), 138.1 (C), 131.8 (C),
131.2 (CH), 130.3 (C), 127.3 (CH), 126.2 (CH), 126.1 (CH), 123.6
(C), 122.1 (CH), 120.9 (CH), 119.1 (CH), 17.9 (CH3).
N-(2-methyl-5-nitrophenyl)-1,3-benzothiazol-2-amine (3m).
Following the general procedure and purication: petroleum
ether–AcOEt: (8 : 2, v/v), 3m was obtained as a green solid (82
1
ꢀ
mg, 58%). Mp: 198–199 C (degradation); H NMR (400 MHz,
DMSO-d6) d 9.92 (bs, 1H, NH), 9.27 (s, 1H), 7.90–7.83 (m, 2H),
7.61 (d, J ¼ 8.0 Hz, 1H), 7.52 (d, J ¼ 8.4 Hz, 1H), 7.35 (t, J ¼ 7.7
Hz, 1H), 7.20 (t, J ¼ 7.6 Hz, 1H), 2.45 (s, 3H); 13C NMR (101 MHz,
DMSO-d6) d 162.5 (C), 151.2 (C), 146.2 (CH), 139.5 (C), 136.0 (C),
131.4 (CH), 130.4 (C), 126.0 (CH), 122.7 (CH), 121.2 (CH), 119.5
(C), 117.6 (CH), 114.7 (CH), 18.5 (CH3). HRMS (ESI): m/z [M + H]+
calc. for C14H12N3O2S 286.0644, found 286.0644.
Acknowledgements
We acknowledge the Region Centre Val de Loire for nancial
support of Geoffrey Dumonteil.
N-(4-bromophenyl)-1,3-benzothiazol-2-amine (3i).6a Follow-
ing the general procedure and purication: petroleum ether–
AcOEt: (8 : 2, v/v), 3i was obtained as a pale purple solid (189
mg, 75%). Mp: 219–220 ꢀC (litt 217–219 ꢀC); 1H NMR (400 MHz,
DMSO-d6) d 10.60 (s, 1H, NH), 7.82 (d, J ¼ 7.9 Hz, 1H), 7.77 (d, J
¼ 8.7 Hz, 2H), 7.62 (d, J ¼ 8.0 Hz, 1H), 7.53 (d, J ¼ 8.8 Hz, 2H),
7.34 (t, J ¼ 7.7 Hz, 1H), 7.17 (t, J ¼ 7.5 Hz, 1H); 13C NMR (101
MHz, DMSO-d6) d 161.2 (C), 151.9 (C), 139.9 (C), 131.7 (CH),
Notes and references
1 (a) S. J. Hays, M. J. Rice, D. F. Ortwine, G. Johnson,
R. D. Schwartz, D. K. Boyd, L. F. Copeland, M. G. Vartanian
and P. A. Boxer, J. Pharm. Sci., 1994, 83, 1425; (b)
T. Soneda, H. Takeshita, K. Kagoshima, Y. Yamamoto,
T. Hosokawa, T. Konosu, N. Masuda, T. Uchida, I. Achiwa,
J. Kuroyanagi, T. Fujisawa, A. Yokomizo and T. Noguchi,
73520 | RSC Adv., 2016, 6, 73517–73521
This journal is © The Royal Society of Chemistry 2016