1854
D. Zhang et al. / Tetrahedron 69 (2013) 1849e1856
d
(ppm) 12.75 (s, 1H), 8.45 (s, 1H), 7.75 (d, J¼7.8 Hz, 2H), 7.63 (d,
J¼8.4 Hz, 2H), 7.55e7.50 (m, 4H), 7.36e7.35 (m, 1H), 7.04e7.01 (m,
3H), 5.73e5.72 (m, 1H); 13C NMR (DMSO-d6, 150 MHz):
(ppm)
J¼8.4 Hz, 3H), 7.96e7.93 (m, 3H), 7.83 (d, J¼8.4 Hz, 1H), 7.79 (d,
J¼8.4 Hz, 1H), 7.60e7.56 (m, 4H), 7.36 (s, 1H), 7.09 (s, 1H), 7.01 (s,
d
2H), 6.08 (s, 1H); 13C NMR (DMSO-d6, 150 MHz):
d (ppm) 189.6,
188.1, 153.9, 153.7, 153.6, 142.8, 138.4, 138.3, 137.5, 136.7, 133.9,
129.9, 129.4, 128.8, 128.3, 125.8, 123.9, 117.4, 96.1; IR (KBr, cmꢂ1):
3432, 3247, 1598, 1573, 1537, 1495, 1402, 1290, 1270, 1213, 1156,
1092, 1012, 942, 829, 751; HRMS (APCI): m/z [MþH]þ calcd for
C22H16Cl2NO3: 412.0502; found: 412.0505.
154.2, 143.2, 137.0, 136.4, 134.5, 133.2, 132.3, 132.2, 129.4, 129.3,
128.64, 128.57, 128.4, 128.12, 128.08, 127.6, 127.5, 127.09, 127.07,
126.9, 126.7, 126.2, 126.1, 126.0, 124.7, 124.0, 123.5, 97.0, 90.9; IR
(KBr, cmꢂ1): 3428, 3055, 1602, 1541, 1500, 1360, 1296, 1224, 1193,
1162, 1125, 1064, 790, 747; HRMS (APCI): m/z [MþH]þ calcd for
C30H22NO3: 444.1594; found: 444.1594.
4.3.16. (Z)-1-(4-Bromophenyl)-2-(2-(4-bromophenyl)-2-hydroxy-
2H-benzo[b][1,4]oxazin-3(4H)-ylidene)ethanone (5e). Yield 90%;
yellow solid; mp 213.3e214.9 ꢀC; 1H NMR (DMSO-d6, 600 MHz):
4.3.21. (Z)-1-(Furan-2-yl)-2-(2-(furan-2-yl)-2-hydroxy-2H-benzo[b]
[1,4]oxazin-3(4H)-ylidene)ethanone (5j). Yield 90%; yellow solid;
d
(ppm) 12.75 (s,1H), 8.44 (s, 1H), 7.68 (s, 4H), 7.64 (d, J¼8.4 Hz, 2H),
7.55 (d, J¼8.4 Hz, 2H), 7.35e7.34 (m, 1H), 7.02e7.01 (m, 3H), 5.72 (s,
1H); 13C NMR (DMSO-d6, 150 MHz):
(ppm) 188.2, 154.0, 142.9,
mp 212.1e213.4 ꢀC; 1H NMR (CDCl3, 600 MHz):
d (ppm) 12.50 (s,
1H), 7.48 (s, 1H), 7.46 (s, 1H), 7.00e6.98 (m, 2H), 6.93e6.90 (m, 2H),
d
6.85 (s, 1H), 6.64 (s, 1H), 6.44 (s, 1H), 6.41 (s, 1H), 5.88 (s, 1H),
138.8, 137.8, 131.8, 131.3, 129.1, 128.9, 125.9, 125.8, 124.1, 122.9, 122.7,
117.5, 116.8, 96.3, 89.9; IR (KBr, cmꢂ1): 3421, 3310, 3087, 3059, 1892,
1778, 1599, 1574, 1522, 1495, 1455, 1398, 1310, 1286, 1270, 1223,
1175, 1109, 1075, 1007, 948, 828, 784; HRMS (APCI): m/z [MþH]þ
calcd for C22H16Br2NO3: 499.9491; found: 499.9491.
5.00e4.95 (m, 1H); 13C NMR (DMSO-d6, 150 MHz):
d (ppm) 178.9,
153.2, 152.2, 150.9, 146.4, 144.1, 142.2, 125.7, 117.3, 116.4, 114.8, 114.6,
112.7, 112.6, 110.6, 110.2, 92.9, 89.2; IR (KBr, cmꢂ1): 3445, 2922,
2851, 1623, 1575, 1548, 1497, 1465, 1448, 1386, 1343, 1295, 1239,
1167, 1105, 1084, 1022, 757; HRMS (APCI): m/z [MþH]þ calcd for
C18H14NO5: 324.0866; found: 324.0871.
4.3.17. (Z)-1-(4-Fluorophenyl)-2-(2-(4-fluorophenyl)-2-hydroxy-2H-
benzo[b][1,4]oxazin-3(4H)-ylidene)ethanone (5f). Yield 85%; yellow
4.3.22. (Z)-1-(Benzofuran-2-yl)-2-(2-(benzofuran-2-yl)-2-hydroxy-
2H-benzo[b][1,4]oxazin-3(4H)-ylidene)ethanone (5k). Yield 87%;
yellow solid; mp 223.4e225.3 ꢀC; 1H NMR (DMSO-d6, 600 MHz):
solid; mp 209.4e211.7 ꢀC; 1H NMR (DMSO-d6, 600 MHz):
d (ppm)
12.70 (s, 1H), 8.37 (s, 1H), 7.79 (t, J¼6.9 Hz, 2H), 7.68e7.65 (m, 2H),
7.35e7.34 (m, 1H), 7.31e7.26 (m, 4H), 7.05e7.04 (m, 1H), 7.03e7.00
d
(ppm) 12.61 (s, 1H), 9.02 (s, 1H), 7.78 (d, J¼7.2 Hz, 1H), 7.72 (d,
(m, 2H), 5.69 (s, 1H); 13C NMR (DMSO-d6, 150 MHz):
d
(ppm) 188.1,
J¼7.2 Hz,1H), 7.65e7.61 (m, 3H), 7.46 (t, J¼7.5 Hz,1H), 7.40e7.29 (m,
188.0, 165.1, 163.4, 163.2, 161.6, 153.7, 142.8, 135.74, 135.66, 135.4,
129.54, 129.48, 129.23, 129.17, 126.0, 125.9, 123.8, 122.8, 117.5, 116.6,
116.5, 115.7, 115.6, 115.2, 115.0, 96.2, 89.9; 19F NMR (DMSO-d6,
4H), 7.15 (s, 1H), 7.09 (s, 1H), 7.06 (s, 2H), 6.14 (s, 1H); 13C NMR
(DMSO-d6, 150 MHz): d (ppm) 179.7, 154.7, 154.6, 153.8, 153.2, 152.0,
142.3, 127.4, 126.9, 125.5, 125.3, 124.5, 124.3, 123.8, 123.2, 123.1,
122.2, 122.1, 117.5, 117.2, 117.0, 111.7, 110.5, 107.0, 106.9, 93.0; IR (KBr,
cmꢂ1): 3444, 1602, 1569, 1529, 1500, 1444, 1382, 1352, 1301, 1253,
1224, 1166, 1142, 1099, 1072, 989, 741; HRMS (APCI): m/z [MþH]þ
calcd for C26H18NO5: 424.1179; found: 424.1179.
376 MHz):
d
(ppm) ꢂ108.43 (s, 1F), ꢂ112.85 (s, 1F); IR (KBr, cmꢂ1):
3430, 3236, 3074, 2590, 1590, 1535, 1514, 1497, 1410, 1389, 1320,
1270, 1229, 1186, 1154, 1113, 1069, 990, 841, 787; HRMS (APCI): m/z
[MþH]þ calcd for C22H16F2NO3: 380.1093; found: 380.1093.
4.3.18. (Z)-2-(2-Hydroxy-2-(4-nitrophenyl)-2H-benzo[b][1,4]oxazin-
4.3.23. (Z)-2-(2-Hydroxy-8-methyl-2-phenyl-2H-benzo[b][1,4]ox-
3(4H)-ylidene)-1-(4-nitrophenyl)ethanone (5g). Yield 97%; red
azin-3(4H)-ylidene)-1-phenylethanone (5l). Yield 82%; yellow solid;
solid; mp 276.4e278.9 ꢀC; 1H NMR (DMSO-d6, 600 MHz):
d
(ppm)
mp 262.5e264.2 ꢀC; 1H NMR (DMSO-d6, 600 MHz):
d (ppm) 13.23
12.87 (s, 1H), 8.80 (s, 1H), 8.32 (d, J¼7.2 Hz, 2H), 8.28 (d, J¼7.8 Hz,
2H), 7.97 (d, J¼7.8 Hz, 2H), 7.92 (d, J¼7.8 Hz, 2H), 7.45e7.44 (m, 1H),
7.09e7.07 (m, 3H), 5.73 (s, 1H); 13C NMR (DMSO-d6, 150 MHz):
(s,1H), 8.30 (s,1H), 7.71 (d, J¼6.6 Hz, 2H), 7.65e7.64 (m, 2H), 7.52 (d,
J¼6.6 Hz, 1H), 7.46 (s, 5H), 6.94 (s, 3H), 5.73 (s, 1H), 2.38 (s, 3H); 13C
NMR (DMSO-d6, 150 MHz): d (ppm) 189.8, 154.7, 143.0, 139.4, 138.8,
d
(ppm) 187.3, 153.9, 153.7, 153.6, 145.9, 143.8, 142.7, 128.4, 128.2,
131.8, 129.2, 128.7, 128.2, 126.8, 124.4, 123.9, 123.3, 115.5, 115.3, 96.3,
90.3, 90.1, 16.1; IR (KBr, cmꢂ1): 3446, 1603, 1580, 1532, 1473, 1449,
1394, 1308, 1275, 1209, 1146, 1088, 1067, 1026, 959, 772, 698; HRMS
(APCI): m/z [MþH]þ calcd for C23H20NO3: 358.1438; found:
358.1438.
125.5, 124.5, 123.6, 123.3, 123.1, 117.8. 117.2, 96.0; IR (KBr, cmꢂ1):
3449, 3111, 2790, 2609, 1583, 1522, 1411, 1349, 1288, 1215, 1188,
1114, 1078, 1000, 847, 754, 699; HRMS (APCI): m/z [MþH]þ calcd for
C22H16N3O7: 434.0983; found: 434.0982.
4.3.19. (Z)-2-(2-Hydroxy-2-(naphthalen-1-yl)-2H-benzo[b][1,4]ox-
azin-3(4H)-ylidene)-1-(naphthalen-1-yl)ethanone (5h). Yield 92%;
yellow solid; mp 261.3e263.7 ꢀC; 1H NMR (DMSO-d6, 600 MHz):
4.3.24. (Z)-2-(6-Fluoro-2-hydroxy-2-phenyl-2H-benzo[b][1,4]ox-
azin-3(4H)-ylidene)-1-phenylethanone (5m). Yield 56%; yellow
solid; mp 203.4e205.8 ꢀC; 1H NMR (CDCl3, 600 MHz):
d (ppm)
d
(ppm) 12.85 (s, 1H), 8.53 (s, 1H), 8.16 (d, J¼6.0 Hz, 1H), 8.02e8.00
12.84 (s,1H), 7.72 (t, J¼8.7 Hz, 4H), 7.46 (s, 4H), 7.38 (t, J¼7.2 Hz, 2H),
(m, 3H), 7.90 (d, J¼8.4 Hz, 1H), 7.86 (d, J¼7.8 Hz, 1H), 7.73 (d,
J¼8.4 Hz, 1H), 7.59e7.54 (m, 4H), 7.44e7.39 (m, 2H), 7.31 (d,
J¼6.6 Hz, 1H), 7.12 (q, J¼6.6 Hz, 2H), 7.05 (t, J¼7.8 Hz, 1H), 7.00 (d,
6.95 (t, J¼6.3 Hz, 1H), 6.72 (d, J¼8.4 Hz, 1H), 6.66 (t, J¼8.4 Hz, 1H),
5.82 (s, 1H), 3.68 (s, 1H); 13C NMR (DMSO-d6, 150 MHz):
d (ppm)
189.7, 158.2, 156.6, 153.1, 139.24, 139.17, 138.7, 132.0, 129.3, 128.7,
128.2, 127.2, 126.9, 126.8, 118.4, 118.3, 109.5, 103.7, 103.6, 96.7, 96.6,
J¼7.8 Hz, 1H), 5.05 (s, 1H); 13C NMR (DMSO-d6, 150 MHz):
d (ppm)
193.4, 142.6, 138.6, 134.6, 134.5, 134.0, 133.2, 130.6, 130.1, 129.0,
128.8, 128.4, 126.5, 126.25, 126.19, 126.1, 125.9, 125.8, 125.7, 125.6,
125.0, 124.7,124.5,124.0,122.9, 117.8, 117.0,116.9, 96.6, 95.5; IR (KBr,
cmꢂ1): 3566, 3451, 3048, 1599, 1559, 1497, 1453, 1347, 1289, 1253,
1215, 1180, 1121, 1083, 1005, 802, 777; HRMS (APCI): m/z [MþH]þ
calcd for C30H22NO3: 444.1594; found: 444.1595.
91.0; 19F NMR (CDCl3, 376 MHz):
d
(ppm) ꢂ119.04 (s, 1F); IR (KBr,
cmꢂ1): 3447, 1604, 1533, 1505, 1450, 1386, 1320, 1280, 1217, 1180,
1103, 1063, 992, 759, 696; HRMS (APCI): m/z [MþH]þ calcd for
C22H17FNO3: 362.1187; found: 362.1187.
4.3.25. 2,4-Diphenylpyrazolo[1,5-a]quinoxaline 1-oxide (7a). Yield
80%; yellow solid; mp 265.4e266.2 ꢀC; 1H NMR (CDCl3, 600 MHz):
4.3.20. (Z)-2-(2-Hydroxy-2-(naphthalen-2-yl)-2H-benzo[b][1,4]ox-
azin-3(4H)-ylidene)-1-(naphthalen-2-yl)ethanone (5i). Yield 96%;
yellow solid; mp 247.1e249.3 ꢀC; 1H NMR (DMSO-d6, 600 MHz):
d
(ppm) 9.99e9.98 (m, 1H), 8.28 (d, J¼7.8 Hz, 2H), 8.120e8.115 (m,
1H), 8.01 (s, 2H), 7.64e7.61 (m, 5H), 7.52 (t, J¼7.2 Hz, 2H), 7.45 (t,
J¼6.9 Hz,1H), 7.20 (s,1H); 13C NMR (CDCl3,150 MHz):
d (ppm) 151.7,
d
(ppm) 12.92 (s, 1H), 8.53 (s, 1H), 8.36 (s, 1H), 8.21 (s, 1H), 8.00 (d,
137.0, 136.2, 133.1, 130.6, 129.5, 129.0, 128.8, 128.7, 128.4, 127.6,