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4.2.2.22. 1,4-Di-N-oxide-7-methoxy-3-methylquinoxaline-2-car-
boxylic acid 2-phenylethylamide (26). Yield, 36%. IR (KBr), 3180
(m, NH); 1665 (s, CO); 1329 (s, N+Oꢀ). 1H MNR (400 MHz, DMSO-
Anal. Calcd for C19H19N3O4, C, 64.59; H, 5.38; N, 11.90. Found: C,
64.25; H, 5.24; N, 11.81.
d6)
d
ppm, 8.93 (t, 1H,
J
NH–CH2 = 5.5 Hz, NH); 8.40 (d, 1H,
4.2.2.29. 3,7-Dimethyl-1,4-di-N-oxidequinoxaline-2-carboxylic
acid 2-(4-methoxyphenyl)-ethylamide (33). Yield, 19.11%. IR
(KBr), 3209 (m, NH); 1666 (s, CO); 1329 (s, N+Oꢀ). 1H MNR
(400 MHz, DMSO-d6) d ppm, 8.88 (t, 1H, JNH–CH2 = 5.5 Hz, NH);
8.38 (d, 1H, JH5–H6 = 8.9 Hz, H5); 8.26 (s, 1H, H8); 7.81 (d, 1H, H6);
JH5–H6 = 9.5 Hz, H5); 7.77 (d, 1H, JH8–H6 = 2.5 Hz, H8); 7.60 (dd, 1H,
H6); 7.36–7.23 (m, 5H, Ph); 3.99 (s, 3H, OCH3); 3.61–3.56 (m, 2H,
NH–CH2); 2.87 (t, 2H, JCH2–Ph = 7.02 Hz, CH2–Ph); 2.22 (s, 3H,
CH3). Anal. Calcd for C19H19N3O4, C, 64.59; H, 5.38; N, 11.90. Found:
C, 64.46; H, 5.44; N, 11.66.
0
0
0
0
0
0
7.22 (d, 2H, JH2 –H3 = 8.2 Hz, H2 +H6 ); 6.89 (d, 2H, H3 +H5 ), 3.72
(s, 3H, OCH3); 3.56–3.52 (m, 2H, NH–CH2); 2.80 (t, 2H,
JCH2–Ph = 7.0 Hz, CH2–Ph); 2.58 (s, 3H, CH3–C7); 2.25 (s, 3H, CH3–
C3). Anal. Calcd for C20H21N3O4, C, 65.40; H, 5.72; N, 11.44. Found:
C, 65.62; H, 5.66; N, 11.58.
4.2.2.23. 7-Chloro-1,4-di-N-oxide-3-methylquinoxaline-2-car-
boxylic acid 2-phenylethylamide (27). Yield, 44%. IR (KBr), 3224
(m, NH); 1667 (s, CO); 1324 (s, N+Oꢀ). 1H MNR (400 MHz, DMSO-
d6)
d ppm, 8.91 (t, 1H, JNH–CH2 = 5.2 Hz, NH); 8.49 (d, 1H,
J
H5–H6 = 9.2 Hz, H5); 8.45 (d, 1H, JH8–H6 = 2.3 Hz, H8); 8.03 (dd, 1H,
4.2.2.30. 1,4-Di-N-oxide-3,6,7-trimethylquinoxaline-2-carbox-
ylic acid 2-(4-methoxyphenyl)-ethylamide (34). Yield, 52.94%.
IR (KBr), 3203 (m, NH); 1665 (s, CO); 1326 (s, N+Oꢀ). 1H MNR
(400 MHz, DMSO-d6) d ppm, 8.90 (t, 1H, JNH–CH2 = 5.6 Hz, NH);
H6); 7.36–7.29 (m, 5H, Ph); 3.62–3.57 (m, 2H, NH–CH2); 2.87 (t,
JCH2–Ph = 7.1 Hz, 2H, CH2–Ph); 2.23 (s, 3H, CH3). Anal. Calcd for
C18H16ClN3O3, C, 60.42; H, 4.47; N, 11.75. Found: C, 60.14; H,
4.50; N, 11. 58.
0
8.26 (s, 1H, H5); 8.22 (s, 1H, H8); 7.22 (d, 2H, JH2 –H3 = 8.5 Hz,
0
0
0
0
H2 +H6 ); 6.88 (d, 2H, H3 +H5 ); 3.73 (s, 1H, OCH3); 3.56–3.51 (m,
2H, NH–CH2); 2.79 (t, 2H, JCH2–Ph = 7.1 Hz, CH2–Ph); 2.46 (s, 6H,
CH3–C7+CH3–C6); 2.25 (s, 3H, CH3–C3). Anal. Calcd for C21H23N3O4,
C, 66.14; H, 6.04; N, 11.02. Found: C, 66.02; H, 6.09; N, 10.99.
4.2.2.24. 6,7-Dichloro-1,4-di-N-oxide-3-methylquinoxaline-2-
carboxylic acid 2-phenylethylamide (28). Yield, 38%. IR (KBr),
3231 (m, NH); 1666 (s, CO); 1322 (s, N+Oꢀ). 1H MNR (400 MHz,
DMSO-d6) d ppm, 88.93 (t, 1H, JNH–CH2 = 5.6 Hz, NH); 8.66 (s, 1H,
H5); 8.64 (s, 1H, H8); 7.34–7.22 (m, 5H, Ph); 3.62–3.57 (m, 2H,
NH–CH2); 2.87 (t, 2H, JCH2–Ph = 7.0 Hz, CH2–Ph); 2.24 (s, 3H, CH3–
C3). Anal. Calcd for C18H15Cl2N3O3, C, 55.10; H, 3.82; N, 10.71.
Found: C, 54.70; H, 3.92; N, 10.44.
4.2.2.31. 1,4-Di-N-oxide-7-methoxy-3-methylquinoxaline-2-
carboxylic acid 2-(4-methoxyphenyl)-ethylamide (35). Yield,
20.97%. IR (KBr), 3221 (m, NH); 1666 (s, CO); 1325 (s, N+Oꢀ). 1H
MNR (400 MHz, DMSO-d6) d ppm, 8.89 (t, 1H, JNH–CH2 = 5.5 Hz,
NH); 8.40 (d, 1H, JH5–H6 = 9.5 Hz, H5); 7.76 (d, 1H, JH8–H6 = 2.7 Hz,
0
0
0
0
4.2.2.25. 1,4-Di-N-oxide-7-fluoro-3-methylquinoxaline-2-car-
boxylic acid 2-phenylethylamide (29). Yield, 77%. IR (KBr), 3231
(m, NH); 1669 (s, CO); 1328 (s, N+Oꢀ). 1H MNR (400 MHz, DMSO-
d6) d ppm, 8.92 (t, 1H, JNH–CH2 = 5.7 Hz, NH); 8.56 (dd, 1H,
H8); 7.59 (dd, 1H, H6); 7.22 (d, 2H, JH2 –H3 = 8.6 Hz, H2 +H6 ); 6.88
0
0
0
(d, 2H, H3 +H5 ); 3.98 (s, 3H, OCH3–C7); 3.72 (s, 3H, OCH3–C4 );
3.57–3.52 (m, 2H, NH–CH2); 2.80 (t, 2H, JCH2–Ph = 7.1 Hz, CH2–Ph);
2.22 (s, 3H, CH3). Anal. Calcd for C20H21N3O5, C, 62.66; H, 5.48; N,
10.97. Found: C, 62.37; H, 5.66; N, 10.66.
JH5–H6 = 9.5 Hz, JH5–F = 5.2 Hz, H5); 8.20 (dd, 1H, JH8–F = 8.8 Hz,
H8–H6 = 2.5 Hz, H8); 7.91 (ddd, 1H, JH6–F = 8.0 Hz, H6); 7.36–7.23
J
(m, 5H, Ph); 3.62–3.57 (m, 2H, NH–CH2); 2.87 (t, 2H,
JCH2–Ph = 7.0 Hz, CH2–Ph); 2.23 (s, 3H, CH3). Anal. Calcd for
C18H16FN3O3, C, 63.34; H, 4.69; N, 12.32. Found: C, 63.02; H,
4.80; N, 12.32.
4.2.2.32. 7-Chloro-1,4-di-N-oxide-3-methylquinoxaline-2-car-
boxylic acid 2-(4-methoxyphenyl)-ethylamide (36). Yield,
48.00%. IR (KBr), 3287 (m, NH); 1655 (s, CO); 1328 (s, N+Oꢀ). 1H
MNR (400 MHz, DMSO-d6) d ppm, 8.87 (s, 1H, NH); 8.49 (d,1H,
JH5–H6 = 9.3 Hz, H5); 8.45 (d, 1H, JH8–H6 = 2.1 Hz, H8); 8.02 (dd, 1H,
0
0
0
0
0
0
4.2.2.26. 6,7-Difluoro-1,4-di-N-oxide-3-methylquinoxaline-2-
carboxylic acid 2-phenylethylamide (30). Yield, 39%. IR (KBr),
3240 (m, NH); 1668 (s, CO); 1332 (s, N+Oꢀ). 1H MNR (400 MHz,
DMSO-d6) d ppm, 8.93 (t, 1H, JNH–CH2 = 5.6 Hz, NH); 8.53–8.47 (m,
2H, H6+H8); 7.36–7.20 (m, 5H, Ph); 3.61–3.56 (m, 2H, NH–CH2);
2.87 (t, 2H, JCH2–Ph = 7.1 Hz, CH2–Ph); 2.24 (s, 3H, CH3). Anal. Calcd
for C18H15F2N303, C, 60.17; H, 4.18; N, 11.70. Found: C, 60.32; H,
4.34; N, 11.87.
H6); 7.22 (d, 2H, JH2 –H3 = 8.5 Hz, H2 +H6 ); 6.88 (d, 2H, H3 +H5 );
3.73 (s, 3H, OCH3); 3.57–3.52 (m, 2H, NH–CH2); 2.80 (t, 2H,
JCH2–Ph = 7.0 Hz, CH2–Ph); 2.26 (s, 3H, CH3). Anal. Calcd for
C19H18ClN3O4, C, 58.84; H, 4.65; N, 10.84. Found: C, 58.62; H,
4.72; N, 10.40.
4.2.2.33. 6,7-Dichloro-1,4-di-N-oxide-3-methylquinoxaline-2-
carboxylic acid 2-(4-methoxyphenyl)-ethylamide (37). Yield,
28.40%. IR (KBr), 3230 (m, NH); 1667 (s, CO); 1324 (s, N+Oꢀ). 1H
MNR (400 MHz, DMSO-d6) d ppm, 8.90 (t, 1H, JNH–CH2 = 5.6 Hz,
4.2.2.27. 1,4-Di-N-oxide-3-methyl-7-trifluoromethylquinoxa-
line-2-carboxylic acid 2-phenylethylamide (31). Yield, 9%. IR
(KBr), 3243 (m, NH); 1669 (s, CO); 1323 (s, N+Oꢀ). 1H MNR
(400 MHz, DMSO-d6) d ppm, 8.93 (t, 1H, JNH–CH2 = 5.4 Hz, NH);
8.74 (s, 1H, H8); 8.66 (d, 1H, JH5–H6 = 9.2 Hz, H5); 8.27 (d, 1H, H6);
7.33–7.31 (m, 5H, Ph); 3.58–3.63 (m, 2H, NH–CH2); 2.88 (t,
JCH2–Ph = 7.0 Hz, 2H, CH2–Ph); 2.27 (s, 3H, CH3). Anal. Calcd for
C19H16F3N3O3, C, 58.31; H, 4.09; N, 10.74. Found: C, 58.10; H,
4.025; N, 10.76.
0
0
NH); 8.66 (s, 1H, H5); 8.64 (s, 1H, H8); 7.22 (d, 2H, JH2 –H3 = 8.5 Hz,
0
0
0
0
H2 +H6 ); 6.88 (d, 2H, H3 +H5 ); 3.72 (s, 1H, OCH3); 3.57–3.52 (m, 2H,
NH–CH2); 2.79 (t, 2H, JCH2–Ph = 6.9 Hz, CH2–Ph); 2.26 (s, 3H, CH3).
Anal. Calcd for C19H17Cl2N3O4, C, 54.03; H, 4.03; N, 9.95. Found:
C, 53.66; H, 3.92; N, 9.65.
4.2.2.34. 1,4-Di-N-oxide-7-fluoro-3-methylquinoxaline-2-car-
boxylic acid 2-(4-methoxyphenyl)-ethylamide (38). Yield,
18.76%. IR (KBr), 3223 (m, NH); 1668 (s, CO); 1330 (s, N+Oꢀ). 1H
MNR (400 MHz, DMSO-d6) d ppm, 8.88 (t, 1H, JNH–CH2 = 5.6 Hz,
NH); 8.56 (dd, 1H JH5–H6 = 9.4 Hz, JH5–F = 5.2 Hz, H5); 8.20 (dd, 1H,
JH8–F = 8.8 Hz, JH8–H6 = 2.8 Hz, H8); 7.94–7.81 (m, 1H, H6); 7.22 (d,
2H, JH2 –H3 = 8.6 Hz, H2 +H6 ); 6.88 (d, 2H, H3 +H5 ); 3.72 (s, 3H,
OCH3); 3.57–3.52 (m, 2H, NH–CH2); 2.80 (t, 2H, JCH2–Ph = 7.1 Hz,
CH2–Ph); 2.28 (s, 3H, CH3). Anal. Calcd for C19H18FN3O4, C, 61.46;
H, 4.85; N, 11.32. Found: C, 61.10; H, 4.78; N, 11.54.
4.2.2.28. 1,4-Di-N-oxide-3-methylquinoxaline-2-carboxylic acid
2-(4-methoxyphenyl)-ethylamide (32). Yield, 10,90%. IR (KBr),
3212 (m, NH); 1670 (s, CO); 1328 (s, N+Oꢀ). 1H MNR (400 MHz,
DMSO-d6) d ppm, 8.88 (t, 1H, JNH–CH2 = 5.5 Hz, NH); 8.48–8.46 (m,
0
0
0
0
0
0
0
0
2H, H5+H8); 8.00–7.98 (m, 2H, H6+H7); 7.22 (d, 2H, JH2 –H3 = 8.6 Hz,
0
0
0
0
H2 +H6 ); 6.88 (d, 2H, H3 +H5 ), 3.72 (s, 3H, OCH3); 3.57–3.52 (m, 2H,
NH–CH2); 2.80 (t, 2H, JCH2–Ph = 7.1 Hz, CH2–Ph); 2.28 (s, 3H, CH3).