J. Xiang et al. / Tetrahedron 68 (2012) 4609e4620
4619
3H). 13C NMR (CDCl3, 75 MHz)
127.1, 84.0, 40.5, 18.8.
d
137.4, 134.5, 130.0, 129.0, 127.6,
126.9, 122.6, 31.7, 29.2, 11.5. HRMS (ESI) calcd for C12H11BrN2NaO3
[MþNa]þ: 332.9851, found: 332.9848.
4.2.33. 2-(2-Nitropropyl)furan (4l). Pale yellow oil, 91% yield. 1H
NMR (CDCl3, 300 MHz)
4.2.42. 5-(2-Methoxyphenethyl)-3-methyl-4-nitroisoxazole (6i). Yellow
d
7.33 (d, J¼0.8 Hz, 1H), 6.29 (d, J¼1.8 Hz,
solid, 80% yield. 1H NMR (CDCl3, 300 MHz)
d
7.26e7.19 (m, 1H),
7.12e7.09 (m, 1H), 6.89e6.84 (m, 2H), 3.82 (s, 3H), 3.51e3.46 (m, 2H),
3.12e3.07 (m, 2H), 2.54 (s, 3H). 13C NMR (CDCl3, 75 MHz)
174.9,157.3,
1H), 6.12 (d, J¼3.1 Hz, 1H), 4.88e4.81 (m, 1H), 3.36 (dd, J1¼15.2 Hz,
J2¼7.3 Hz,1H), 3.08 (dd, J1¼15.2 Hz, J2¼6.5 Hz,1H),1.57 (d, J¼6.7 Hz,
d
3H). 13C NMR (CDCl3, 75 MHz)
33.4, 18.8.
d
149.3, 142.3, 110.5, 108.0, 81.8,
155.4, 129.9, 128.1, 127.1, 120.4, 110.1, 55.1, 27.7, 27.5, 11.6. HRMS (ESI)
calcd for C13H14N2NaO4 [MþNa]þ: 285.0851, found: 285.0841.
4.2.34. 3-Methyl-4-nitro-5-phenethylisoxazole (6a). White solid,
95% yield. 1H NMR (CDCl3, 300 MHz)
7.34e7.30 (m, 2H), 7.26e7.22
(m, 3H), 3.53e3.48 (m, 2H), 3.13e3.07 (m, 2H), 2.55 (s, 3H). 13C NMR
4.2.43. 5-(2-Chlorophenethyl)-3-methyl-4-nitroisoxazole (6j). White
d
solid, 83% yield. 1H NMR (CDCl3, 300 MHz)
d
7.38e7.34 (m, 1H),
7.20e7.17 (m, 3H), 3.54e3.49 (m, 2H), 3.24e3.19 (m, 2H), 2.55 (s, 3H).
13C NMR (CDCl3, 75 MHz)
173.8, 155.6, 136.5, 133.9, 130.4, 129.7,
(CDCl3, 75 MHz)
d
174.1, 155.6, 138.9, 128.7, 128.2, 126.7, 32.2, 29.5,
d
11.6. HRMS (ESI) calcd for C12H12N2NaO3 [MþNa]þ: 255.0746,
128.4, 127.1, 30.2, 27.6, 11.6. HRMS (ESI) calcd for C12H11ClN2NaO3
found: 255.0736.
[MþNa]þ: 289.0356, found: 289.0349.
4.2.35. 5-(4-Methoxyphenethyl)-3-methyl-4-nitroisoxazole (6b). Yel-
4.2.44. 2-(2-(3-Methyl-4-nitroisoxazol-5-yl)ethyl)benzonitrile
low solid, 84% yield. 1H NMR (CDCl3, 300 MHz)
d
7.13 (d,
(6k). White solid, 63% yield. 1H NMR (CDCl3, 300 MHz)
d
7.61e7.58
(m, 2H), 7.35e7.32 (m, 2H), 3.54e3.49 (m, 2H), 3.19e3.14 (m, 2H),
2.54 (s, 3H). 13C NMR (CDCl3, 75 MHz)
173.1, 155.6, 144.3, 132.5,
J¼8.4 Hz, 2H), 6.83 (d, J¼8.5 Hz, 2H), 3.78 (s, 3H), 3.48e3.43 (m,
2H), 3.06e3.00 (m, 2H), 2.54 (s, 3H). 13C NMR (CDCl3, 75 MHz)
d
d
174.3, 158.3, 155.6, 130.9, 129.2, 114.0, 55.2, 31.4, 29.8, 11.6.
129.1, 118.6, 110.7, 32.1, 28.8, 11.5. HRMS (ESI) calcd for
HRMS (ESI) calcd for C13H14N2NaO4 [MþNa]þ: 285.0851, found:
C13H11N3NaO3 [MþNa]þ: 280.0698, found: 280.0696.
285.0836.
4.2.45. 3-Methyl-5-(2-(naphthalen-1-yl)ethyl)-4-nitroisoxazole (6l).
4.2.36. 3-Methyl-5-(4-methylphenethyl)-4-nitroisoxazole (6c). White
White solid, 54% yield. 1H NMR (CDCl3, 300 MHz)
d
8.12 (d, J¼8.3 Hz,
solid, 81% yield. 1H NMR (CDCl3, 300 MHz)
d
7.12 (m, 4H), 3.51e3.45
1H), 7.89 (d, J¼7.9 Hz, 1H), 7.78 (d, J¼7.8 Hz, 1H), 7.62e7.50 (m, 2H),
(m, 2H), 3.09e3.03 (m, 2H), 2.56 (s, 3H), 2.33 (s, 3H). 13C NMR (CDCl3,
7.45e7.36 (m, 2H), 3.64e3.51 (m, 4H), 2.57 (s, 3H). 13C NMR (CDCl3,
75 MHz)
d
174.3, 155.5, 136.3, 135.8, 129.3, 128.1, 31.8, 29.6, 20.9, 11.6.
75 MHz) d 174.2, 155.7, 135.0, 133.8, 131.3, 129.0, 127.7, 126.4, 126.3,
HRMS (ESI) calcd for C13H14N2NaO3 [MþNa]þ: 269.0902, found:
125.8, 125.5, 123.0, 29.7, 28.9, 11.6. HRMS (ESI) calcd for
269.0893.
C16H14N2NaO3 [MþNa]þ: 305.0902, found: 305.0893.
4.2.37. 5-(4-Fluorophenethyl)-3-methyl-4-nitroisoxazole (6d). White
4.2.46. 3-Methyl-4-nitro-5-(2-(thiophen-2-yl)ethyl)isoxazole
solid, 91% yield. 1H NMR (CDCl3, 300 MHz)
d
7.19e7.15 (m, 2H),
6.97 (t, J¼8.7 Hz, 2H), 3.49e3.44 (m, 2H), 3.09e3.04 (m, 2H),
2.53 (s, 3H). 13C NMR (CDCl3, 75 MHz)
173.9, 163.2,
(6m). Pale yellow solid, 92% yield. 1H NMR (CDCl3, 300 MHz)
d 7.15
(d, J¼5.1 Hz,1H), 6.93e6.90 (m,1H), 6.84 (d, J¼2.2 Hz,1H), 3.58e3.53
d
(m, 2H), 3.36e3.31 (m, 2H), 2.55 (s, 3H). 13C NMR (CDCl3, 75 MHz)
160.0, 155.5, 134.6, 134.5, 129.8, 129.6, 115.6, 115.3, 31.4, 29.5,
11.5. HRMS (ESI) calcd for C12H11FN2NaO3 [MþNa]þ: 273.0651,
found: 273.0643.
d 173.4, 155.6, 141.1, 127.0, 125.2, 124.2, 29.7, 26.3, 11.6. HRMS (ESI)
calcd for C10H10N2NaO3S [MþNa]þ: 261.0310, found: 261.0307.
4.2.47. 5-(2-Cyclopropylethyl)-3-methyl-4-nitroisoxazole (6n). Yellow
4.2.38. 5-(4-Chlorophenethyl)-3-methyl-4-nitroisoxazole (6e). White
oil, 87% yield. 1H NMR (CDCl3, 300 MHz)
d
3.29e3.24 (m, 2H), 2.53 (s,
solid, 90% yield. 1H NMR (CDCl3, 300 MHz)
d
7.26 (d, J¼8.4 Hz, 2H),
3H), 1.70e1.63 (m, 2H), 0.74e0.71 (m, 1H), 0.47e0.41 (m, 2H),
7.14 (d, J¼8.4 Hz, 2H), 3.49e3.44 (m, 2H), 3.09e3.03 (m, 2H), 2.53 (s,
0.06e0.03 (m, 2H). 13C NMR (CDCl3, 75 MHz)
d 175.3, 155.5, 31.6, 27.8,
3H). 13C NMR (CDCl3, 75 MHz)
d
173.7, 155.6, 137.3, 132.5, 129.6, 128.7,
11.6, 10.4, 4.5. HRMS (ESI) calcd for C9H12N2NaO3 [MþNa]þ: 219.0746,
31.5, 29.3, 11.5. HRMS (ESI) calcd for C12H11ClN2NaO3 [MþNa]þ:
found: 219.0745.
289.0356, found: 289.0352.
Acknowledgements
4.2.39. 5-(4-Bromophenethyl)-3-methyl-4-nitroisoxazole (6f). White
solid, 94% yield. 1H NMR (CDCl3, 300 MHz)
d
7.41 (d, J¼8.3 Hz, 2H),
We thank Prof. Xiaomei Zhang for many discussions on this
project. We are grateful for financial support from the National
Natural Science Foundation of China (No. 20972154), and the Na-
tional Basic Research Program of China (973 Program, No.
2010CB833300).
7.09 (d, J¼8.3 Hz, 2H), 3.49e3.44 (m, 2H), 3.07e3.02 (m, 2H), 2.54 (s,
3H). 13C NMR (CDCl3, 75 MHz)
d 173.7, 155.6, 137.8, 131.7, 130.0, 120.6,
31.6, 29.2, 11.2. HRMS (ESI) calcd for C12H11BrN2NaO3 [MþNa]þ:
332.9851, found: 332.9846.
4.2.40. 5-(3-Fluorophenethyl)-3-methyl-4-nitroisoxazole (6g). White
Supplementary data
solid, 81% yield. 1H NMR (CDCl3, 300 MHz)
d
7.30e7.23 (m, 1H), 6.99
(d, J¼7.7 Hz, 1H), 6.95e6.90 (m, 2H), 3.52e3.46 (m, 2H), 3.12e3.07
(m, 2H), 2.55 (s, 3H). 13C NMR (CDCl3, 75 MHz)
173.7, 164.4, 161.2,
Supplementary data associated with this article can be found in
d
155.6, 141.3, 141.2, 130.2, 130.1, 123.9, 123.8, 115.3, 115.0, 113.8, 113.6,
31.8, 29.2, 11.5. HRMS (ESI) calcd for C12H11FN2NaO3 [MþNa]þ:
273.0651, found: 273.0648.
References and notes
1. Ono, N. The Nitro Group in Organic Synthesis; Wiley-VCH: New York, NY, 2001.
2. Ballini, R.; Petrini, M. Tetrahedron 2004, 60, 1017e1047.
3. Berner, O. M.; Tedeschi, L.; Enders, D. Eur. J. Org. Chem. 2002, 1877e1894.
4. For the examples of selective reduction of conjugated nitroalkenes by boro-
hydrides, see: (a) Barrett, A. G. M.; Graboski, G. G. Chem. Rev. 1986, 86, 751e762;
(b) Verma, R. S.; Kabalka, G. W. Synth. Commun. 1985, 15, 151e155; (c) Kabalka,
4.2.41. 5-(3-Bromophenethyl)-3-methyl-4-nitroisoxazole (6h). White
solid, 83% yield. 1H NMR (CDCl3, 300 MHz)
d
7.37e7.35 (m, 2H),
7.20e7.13 (m, 2H), 3.50e3.45 (m, 2H), 3.08e3.03 (m, 2H), 2.54 (s,
3H). 13C NMR (CDCl3, 75 MHz)
173.6, 155.6, 141.1, 131.3, 130.2, 129.9,
d