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doi.org/10.1002/ejoc.202100756
1H), 7.53–7.49 (m, 1H); 13C{1H} (100 MHz, CDCl3) δ 168.9, 156.9,
3-(3,4-dimethoxyphenyl)benzo[c]isoxazole (2q)
144.7, 132.8, 132.7 131.7, 131.1, 127.5, 125.9, 124.6, 121.1, 117.1,
White solid, yield 92% (54.70 mg), hexane/EtOAc (98:2), 1H NMR
(400 MHz, CDCl3): δ 7.75 (d, J=8.84 Hz, 1H), 7.55 (d, J=9.52 Hz, 2H),
7.50 (s, 1H), 7.29–7.26 (m, 1H), 7.01–6.96 (m, 2H), 3.97 (s, 3H), 3.93 (s,
3H); 13C{1H} (100 MHz, CDCl3): δ 164.4, 157.8, 150.8, 149.5, 130.5,
124.0, 121.2, 120.6, 119.8, 115.2, 113.6, 111.3, 109.3, 56.0 (2 C);
HRMS (ESI-TOF) m/z: [M+Na]+ calcd for C15H13NNaO3+, 278.0788;
found, 278.0779.
+
114.8; HRMS (ESI-TOF) m/z: [M+H]+ calcd for C13H8ClN2O3
,
275.0218; found, 275.0214.
5-bromo-3-(3,4,5-trimethoxyphenyl)benzo[c]isoxazole (2w)
Brown solid, yield 91% (54.30 mg), hexane/EtOAc (98:2), 1H NMR
(500 MHz, CDCl3): δ 7.91–7.89 (m, 1H), 7.49–7.46 (m, 1H), 7.35–7.32
(m, 1H), 7.13–7.12 (m, 2H), 3.97 (s, 6H), 3.93 (s, 3H); 13C{1H} (100 MHz,
CDCl3) δ 164.0, 156.2, 153.9, 140.5, 134.5, 123.0, 122.4, 118.0, 117.1,
115.0, 104.1, 61.0, 56.4(2 C); HRMS (ESI-TOF) m/z: [M+H]+ calcd for
C16H14BrNNaO4+, 385.9998; found, 385.9992.
3-(3,4-difluorophenyl)benzo[c]isoxazole (2r)
White solid, yield 88% (53.26 mg), hexane/EtOAc (98:2), mp 126–
129 C; FT-IR (KBrcmÀ 1) 3429, 3075, 1631, 1515, 1446, 1416, 1273; 1H
°
NMR (400 MHz, CDCl3): δ 7.84–7.79 (m, 1H), 7.77–7.73 (m, 2H), 7.61
(d, J=9.12 Hz, 1H), 7.38–7.31 (m, 2H), 7.11–7.07 (m, 1H); 13C{1H}
2-hydroxyethyl 2-aminobenzoate (2h’’)
1
2
(100 MHz, CDCl3): δ 162.0, 157.8, 151.4 (dd, JC–F =252.71 Hz, JC–F
=
Orange liquid, yield 58% (52.93 mg), hexane/EtOAc (60:40), 1H
NMR (500 MHz, CDCl3): δ 7.88 (dd, J1 =6.44 Hz, J2 =1.50 Hz, 1H),
7.29–7.26 (m, 2H), 6.67–6.63 (m, 2H), 5.72 (s, 2H), 4.42 (t, 2H), 3.94 (t,
2H), 2.12 (s, 1H); 13C{1H} (125 MHz, CDCl3): δ 168.3, 150.6, 134.3,
131.2, 116.7, 116.3, 110.3, 66.1, 61.5; HRMS (ESI-TOF) m/z: [M+Na]+
calcd for C9H11NNaO3+, 204.0631; found, 204.0634.
1
2
12.53 Hz), 150.8 (dd, JC–F =248.74 Hz, JC–F =13.14 Hz), 130.8, 125.3,
3
4
123.07 (d, JC–F =7.07 Hz), 122.9 (d, JC–F =3.37 Hz), 119.8, 118.5 (d,
2JC–F =17.75 Hz), 115.73, 115.70 (d, 2JC–F =19.18 Hz), 114.4; HRMS
(ESI-TOF) m/z: [M+H]+ calcd for C13H8F2NO+, 232.0568; found,
232.0564.
3-(4-fluoro-3-methylphenyl)benzo[c]isoxazole (2s)
2-amino-N-(2-hydroxyethyl)benzamide (2h’)
White solid, yield 89% (52.93 mg), hexane/EtOAc (98:2), mp; 122–
Orange liquid, yield 81% (73.51 mg), hexane/EtOAc (20:80), 1H
NMR (400 MHz, DMSO): δ 8.09 (t, J=5.20 Hz, 1H), 7.48 (d, J=
8.96 Hz, 1H), 7.13–7.09 (m, 1H), 6.67 (d, J=8.76 Hz, 1H), 6.51–6.47
(m, 1H), 6.33 (s, 2H), 4.68 (t, J=5.65 Hz, 1H), 3.50 (q, J=6.12 Hz, 2H),
3.29 (q, J=5.96 Hz, 2H); 13C{1H} (100 MHz, DMSO&CDCl3): δ 169.4,
149.9, 131.9, 128.5, 116.7, 115.3, 114.9, 60.3, 42.2; HRMS (ESI-TOF)
m/z: [M+Na]+ calcd for C9H12NNaO2+, 203.0790; found, 203.0794.
124 C; FT-IR (KBrcmÀ 1) 34330, 2924, 2855, 1603, 1515, 1447, 1273 ;
°
1H NMR (400 MHz, CDCl3): δ 7.85–7.81 (m, 1H), 7.80–7.78 (m, 1H),
7.75 (s, 1H), 7.59 (d, J=9.12 Hz, 1H), 7.33–7.29 (m, 1H), 7.17 (t, 1H),
7.06–7.02 (s, 1H), 2.38 (s, 3H); 13C{1H} (100 MHz, CDCl3): δ 163.7,
162.4 (d, 1JC–F =249.28 Hz), 157.8, 130.6, 129.9 (d, 3JC–F =5.65 Hz),
2
3
126.3 (d, JC–F =17.97 Hz), 125.9 (d, JC–F =8.85 Hz), 124.5, 124.4 (d,
4JC–F =3.79 Hz), 120.4, 116.1 (d, 2JC–F =22.47 Hz), 115.4, 114.0, 14.7;
HRMS (ESI-TOF) m/z: [M+H]+ calcd for C14H11FNO+, 228.0819;
found, 228.0821.
(E)-1,1’-(diazene-1,2-diylbis(2,1-phenylene))bis(ethan-1-one)
(2i’)
5-chloro-3-(2-chlorophenyl)benzo[c]isoxazole (2t)
Orange solid, yield 10% (11.82 mg), hexane/EtOAc (96:4), mp 101–
103 C; FT-IR (KBrcmÀ 1) 3424, 2924, 1692, 1421, 1384, 1236, 1033; 1H
1
°
White solid, yield 87% (51.80 mg), hexane/EtOAc (98:2), H NMR
NMR (400 MHz, CDCl3): δ 7.68–7.65 (m, 4H), 7.58–7.55 (m, 4H), 2.64
(s, 6H); 13C{1H} (100 MHz, CDCl3): δ 202.4, 149.9, 139.2, 131.6, 131.4,
128.3, 117.7, 32.4; HRMS (ESI-TOF) m/z: [M+Na]+calcd for
C16H14N2NaO2+, 289.0947; found, 289.0948.
(500 MHz, CDCl3): δ 7.67–7.65 (m, 1H), 7.63–7.60 (m, 3H), 7.51–7.48
(m, 1H), 7.47–7.44 (m, 1H), 7.28–7.26 (m, 1H); 13C{1H} (125 MHz,
CDCl3): δ 162.9, 155.9, 132.8, 132.6, 131.8, 131.5, 130.9, 130.1, 127.2,
126.9, 119.4, 117.1, 116.5; HRMS (ESI-TOF) m/z: [M+H]+ calcd for
C13H8Cl2NO+, 263.9977; found, 263.9977.
dimethyl 2,2’-(diazene-1,2-diyl)(E)-dibenzoate (2a’’)
5-bromo-3-(2-fluorophenyl)benzo[c]isoxazole (2u)
1
Orange solid, yield 42% (49.73 mg), hexane/EtOAc (97:3), H NMR
(400 MHz, CDCl3): 1H NMR (400 MHz, CDCl3): δ 7.87 (d, J=7.44 Hz,
White solid, yield 86% (51.84 mg), hexane/EtOAc (98:2), mp 107–
2H), 7.63–7.62 (m, 4H), 7.53–7.49 (m, 2H), 3.92 (s, 6H); 13C{1H}
110 C; FT-IR (KBrcmÀ 1) 3419, 3079, 2924, 1627, 1490, 1449, 1217,
°
759, 561; 1H NMR (400 MHz, CDCl3): δ 7.99 (s, 1H), 7.97–7.93 (m, 1H),
(100 MHz, CDCl3): δ 167.3, 152.3, 132.4, 130.0, 129.9, 128.6, 118.6,
+
52.5; HRMS (ESI-TOF) m/z: [M+Na]+ calcd for C16H14N2NaO4
,
7.54–7.49 (m, 2H), 7.38–7.34 (m, 2H), 7.31–7.28 (m, 1H) ; 13C{1H}
2
321.0845; found, 321.0850.
(125 MHz, CDCl3): δ 159.9, 158.6 (d, JC–F =251.65 Hz), 156.2, 134.7,
4
132.4 (d, 3JC–F =8.45 Hz), 129.5 (d, 4JC–F =2.63 Hz), 125.0 (d, JC–F
=
3.40 Hz), 123.3 (d, 2JC–F =14.16 Hz), 118.1 (d, JC–F =2.62 Hz), 116.8,
116.72, 116.70 (d, JC–F =21.47 Hz), 115.9 (d, JC–F =13.91 Hz); HRMS
(ESI-TOF) m/z: [M+H]+ calcd for C13H8BrFNO+, 291.9768; found,
291.9763.
4
2
2
diphenyl 2,2’-(diazene-1,2-diyl)(E)-dibenzoate (2b’’)
1
Orange solid, yield 40% (47.54 mg), hexane/EtOAc (97:3), H NMR
(400 MHz, CDCl3): δ 8.13 (d, J=7.44 Hz, 2H), 7.69–7.61 (m, 4H), 7.59–
7.57 (m, 2H), 7.47–7.44 (m, 4H), 7.32–7.28 (m, 6H); 13C{1H} (100 MHz,
CDCl3): δ 165.0, 153.0, 150.9, 133.2, 130.4, 130.1, 129.5, 127.8, 126.0,
121.7, 118.6, 61.5, 14.3; HRMS (ESI-TOF) m/z: [M+Na]+calcd for
C26H18N2NaO4+, 445.1159; found, 445.1159.
3-(2-chlorophenyl)-5-nitrobenzo[c]isoxazole (2v)
White solid, yield 87% (51.82 mg), hexane/EtOAc (97:3), mp 121–
123 C ; FT-IR (KBrcmÀ 1) 3484, 3318, 2924, 1620, 1512, 1322, 1289,
°
1
764; H NMR (400 MHz, CDCl3): δ 8.75 (s, 1H), 8.11 (dd, J1 =9.76 Hz,
J2 =1.88 Hz, 1H), 7.77–7.70 (m, 2H), 7.66–7.64 (m, 1H), 7.59–7.55 (m,
Eur. J. Org. Chem. 2021, 4125–4131
4130
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