The Journal of Organic Chemistry
Note
1
171.9, 154.4, 154.1, 130.8, 128.8, 128.2, 128.0, 127.8, 120.6, 114.7,
111.7, 109.0, 55.7, 19.5, 14.5; HRMS (ESI), m/z calcd. for
C15H16N2O3 ([M + Na]+) 295.1053, found 295.1055; IR (KBr,
neat) v 3003, 2835, 1760, 1692, 1598, 1505, 1365, 1238, 962, 759, 749.
(E)-1-(1-(3-Methoxyphenyl)-1H-pyrrol-2-yl)ethan-1-one O-
acetyl oxime (1d). The product was isolated by flash chromatog-
raphy (eluent EtOAc:PE = 1:10) as a pale yellow oil (398 mg, 73%):
1H NMR (400 MHz, CDCl3) δ 7.26 (t, J = 8.0 Hz, 1H), 6.88 (t, J =
2.0 Hz, 1H), 6.86−6.82 (m, 3H), 6.68 (dd, J = 3.6, 1.6 Hz, 1H), 6.26
(t, J = 3.6 Hz, 1H), 3.76 (s, 3H), 2.12 (s, 3H), 1.84 (s, 3H); 13C NMR
(100 MHz, CDCl3) δ 170.4, 159.7, 154.6, 141.9, 129.3, 127.7, 127.0,
117.7, 115.2, 112.5, 111.4, 108.9, 55.0, 19.2, 15.0; HRMS (ESI), m/z
calcd. for C15H16N2O3 ([M + Na]+) 295.1053, found 295.1034; IR
(KBr, neat) v 3109, 2838, 1768, 1606, 1491, 1316, 1228, 1197, 928,
733, 693.
(E)-1-(1-(p-Tolyl)-1H-pyrrol-2-yl)ethan-1-one O-acetyl oxime
(1e). The product was isolated by flash chromatography (eluent
EtOAc:PE = 1:10) as a white solid (384 mg, 75%): mp 94−96 °C; 1H
NMR (400 MHz, CDCl3) δ 7.23−7.15 (m, 4H), 6.89 (dd, J = 2.4, 1.6
Hz, 1H), 6.70 (dd, J = 4.0, 2.0 Hz, 1H), 6.29 (dd, J = 4.0, 2.8 Hz, 1H),
2.38 (s, 3H), 2.14 (s, 3H), 1.85 (s, 3H); 13C{1H} NMR (100 MHz,
CDCl3) δ 171.0, 154.9, 138.6, 137.1, 129.4, 128.1, 127.3, 125.5, 115.2,
109.0, 20.9, 19.5, 15.4; HRMS (ESI), m/z calcd. for C15H16N2O2 ([M
+ Na]+) 279.1104, found 279.1097; IR (KBr, neat) v 3110, 1758, 1742,
1605, 1516, 1451, 1366, 1234, 1042, 924, 823, 730.
°C; H NMR (400 MHz, CDCl3) δ 7.47 (dd, J = 6.0, 2.8 Hz, 1H),
7.36−7.31 (m, 3H), 6.78 (d, J = 2.0 Hz, 1H), 6.75 (d, J = 3.6 Hz, 1H),
6.37 (t, J = 3.2 Hz, 1H), 2.28 (s, 3H), 1.69 (s, 3H); 13C NMR (100
MHz, CDCl3) δ 171.4, 153.5, 139.7, 132.2, 129.9, 129.0, 128.9, 127.9,
127.8, 127.3, 115.3, 109.6, 19.5, 14.1; HRMS (ESI), m/z calcd. for
C14H13ClN2O2 ([M + Na]+) 299.0558, found 299.0559; IR (KBr,
neat) v 3110, 1767, 1663, 1489, 1366, 1230, 1198, 1071, 925, 763, 740.
(E)-1-(1-(3-Chlorophenyl)-1H-pyrrol-2-yl)ethan-1-one O-ace-
tyl oxime (1k). The product was isolated by flash chromatography
1
(eluent EtOAc:PE = 1:15) as a yellow oil (421 mg, 76%): H NMR
(400 MHz, CDCl3) δ 7.35−7.30 (m, 3H), 7.22−7.14 (m, 1H), 6.88
(dd, J = 2.4, 1.6 Hz, 1H), 6.73 (dd, J = 3.6, 1.6 Hz, 1H), 6.32 (dd, J =
3.6, 2.8 Hz, 1H), 2.21 (s, 3H), 1.85 (s, 3H); 13C NMR (100 MHz,
CDCl3) δ 170.4, 154.1, 142.2, 134.1, 129.7, 128.1, 127.3, 127.0, 126.2,
124.2, 116.1, 109.6, 19.3, 14.9; HRMS (ESI), m/z calcd. for
C14H13ClN2O2 ([M + Na]+) 299.0558, found 299.0532; IR (KBr,
neat) v 3068, 1768, 1595, 1484, 1366, 1230, 1196, 1092, 927, 731, 689.
(E)-1-(1-(4-(Trifluoromethyl)phenyl)-1H-pyrrol-2-yl)ethan-1-
one O-acetyl oxime (1l). The product was isolated by flash
chromatography (eluent EtOAc:PE = 1:15) as a white solid (478 mg,
77%): mp 71−73 °C; 1H NMR (400 MHz, CDCl3) δ 7.69 (d, J = 8.4
Hz, 2H), 7.42 (d, J = 8.0 Hz, 2H), 6.92 (t, J = 2.0 Hz, 1H), 6.76 (dd, J
= 3.6, 1.2 Hz, 1H), 6.36 (t, J = 3.2 Hz, 1H), 2.22 (s, 3H), 1.81 (s, 3H);
13C{1H} NMR (100 MHz, CDCl3) δ 170.3, 154.5, 144.2, 129.5, 129.1,
128.1, 127.3, 126.3, 126.1 (q, J = 3.6 Hz), 125.5, 125.1, 122.4, 116.6,
110.1, 19.3, 15.2; HRMS (ESI), m/z calcd. for C15H13F3N2O2 ([M +
Na]+) 333.0821, found 333.0822; IR (KBr, neat) v 3071, 1774, 1615,
1454, 1367, 1327, 1180, 1123, 1067, 852, 725.
(E)-1-(1-(o-Tolyl)-1H-pyrrol-2-yl)ethan-1-one O-acetyl oxime
(1f). The product was isolated by flash chromatography (eluent
EtOAc:PE = 1:10) as a white solid (410 mg, 80%): mp 61−62 °C; 1H
NMR (400 MHz, CDCl3) δ 7.29−7.27 (m, 2H), 7.24 (t, J = 3.2 Hz,
1H), 7.20 (d, J = 7.2 Hz, 1H), 6.81−6.71 (m, 2H), 6.35 (t, J = 3.4 Hz,
1H), 2.26 (s, 3H), 2.02 (s, 3H), 1.63 (s, 3H); 13C{1H} NMR (100
MHz, CDCl3) δ 171.9, 153.3, 141.0, 135.4, 130.2, 127.8, 127.2, 127.1,
126.2, 115.0, 109.0, 19.3, 17.1, 14.0; HRMS (ESI), m/z calcd. for
C15H16N2O2 ([M + Na]+) 279.1104, found 279.1102; IR (KBr, neat) v
3022, 1760, 1741, 1602, 1531, 1496, 1366, 1232, 1088, 923, 787, 737.
(E)-1-(1-(m-Tolyl)-1H-pyrrol-2-yl)ethan-1-one O-acetyl
oxime (1g). The product was isolated by flash chromatography
(E)-1-(1-(2-(Trifluoromethyl)phenyl)-1H-pyrrol-2-yl)ethan-1-
one O-acetyl oxime (1m). The product was isolated by flash
chromatography (eluent EtOAc:PE = 2:15) as a white solid (484 mg,
78%): mp 64−66 °C; 1H NMR (400 MHz, CDCl3) δ 7.75 (d, J = 7.6
Hz, 1H), 7.62 (t, J = 7.6 Hz, 1H), 7.52 (t, J = 7.6 Hz, 1H), 7.36 (d, J =
8.0 Hz, 1H), 6.83 (s, 1H), 6.75 (dd, J = 3.6, 1.6 Hz, 1H), 6.34 (dd, J =
3.6, 2.8 Hz, 1H), 2.25 (s, 3H), 1.63 (s, 3H); 13C{1H} NMR (100
MHz, CDCl3) δ 171.0, 153.3, 140.0, 132.4, 130.5, 129.3, 128.5, 128.3,
127.4, 127.1, 126.7 (q, J = 5.0 Hz), 124.4, 121.6, 115.6, 109.2, 19.4,
14.1; HRMS (ESI), m/z calcd. for C15H13F3N2O2 ([M + Na]+)
333.0821, found 333.0826; IR (KBr, neat) v 3062, 1771, 1653, 1599,
1498, 1364, 1196, 1098, 764, 695.
1
(eluent EtOAc:PE = 1:8) as a yellow oil (374 mg, 73%): H NMR
(400 MHz, CDCl3) δ 7.26 (t, J = 7.8 Hz, 1H), 7.12 (d, J = 7.6 Hz,
1H), 7.10 (s, 1H), 7.05 (d, J = 7.6 Hz, 1H), 6.87 (t, J = 2.0 Hz, 1H),
6.69 (dd, J = 3.6, 1.6 Hz, 1H), 6.27 (t, J = 3.4 Hz, 1H), 2.36 (s, 3H),
2.13 (s, 3H), 1.81 (s, 3H); 13C{1H} NMR (100 MHz, CDCl3) δ 170.8,
154.6, 141.0, 138.7, 128.5, 128.0, 127.8, 127.1, 126.3, 122.7, 115.2,
109.0, 21.0, 19.3, 15.1; HRMS (ESI), m/z calcd. for C15H16N2O2 ([M
+ Na]+) 279.1104, found 279.1103; IR (KBr, neat) v 3109, 1768, 1609,
1536, 1493, 1455, 1366, 1231, 1191, 928, 730, 696.
(E)-1-(1-(3-(Trifluoromethyl)phenyl)-1H-pyrrol-2-yl)ethan-1-
one O-acetyl oxime (1n). The product was isolated by flash
chromatography (eluent EtOAc:PE = 1:20) as a yellow oil (503 mg,
1
81%): H NMR (400 MHz, CDCl3) δ 7.61 (d, J = 7.6 Hz, 1H), 7.57
(d, J = 2.0 Hz, 1H), 7.54 (d, J = 8.0 Hz, 1H), 7.49 (d, J = 7.6 Hz, 1H),
6.91 (dd, J = 2.8, 1.6 Hz, 1H), 6.76 (dd, J = 3.6, 1.6 Hz, 1H), 6.35 (dd,
J = 3.6, 2.8 Hz, 1H), 2.25 (s, 3H), 1.78 (s, 3H); 13C{1H} NMR (100
MHz, CDCl3) δ 170.3, 154.1, 141.9, 131.6, 131.2, 129.6, 129.5, 128.4,
127.3, 124.9, 124.0 (q, J = 3.7 Hz), 123.2(q, J = 3.7 Hz), 116.5, 110.0,
19.3, 14.9; HRMS (ESI), m/z calcd. for C15H13F3N2O2 ([M + Na]+)
333.0821, found 333.0824; IR (KBr, neat) v 3116, 1769, 1599, 1496,
1367, 1336, 1129, 1070, 929, 802, 699.
(E)-1-(1-(3,4-Dimethylphenyl)-1H-pyrrol-2-yl)ethan-1-one O-
acetyl oxime (1h). The product was isolated by flash chromatog-
raphy (eluent EtOAc:PE = 1:15) as a white solid (362 mg, 67%): mp
1
89−91 °C; H NMR (400 MHz, CDCl3) δ 7.15 (d, J = 7.6 Hz, 1H),
7.08 (d, J = 2.0 Hz, 1H), 6.99 (dd, J = 8.0, 2.4 Hz, 1H), 6.85 (dd, J =
2.8, 2.0 Hz, 1H), 6.50 (dd, J = 3.6, 2.0 Hz, 1H), 6.26 (dd, J = 3.6, 2.8
Hz, 1H), 2.29 (s, 6H), 1.94 (s, 3H); 13C{1H} NMR (100 MHz,
CDCl3) δ 150.1, 138.6, 137.5, 135.4, 130.0, 129.5, 126.1, 126.0, 122.6,
112.3, 108.7, 19.8, 19.3, 14.2; HRMS (ESI), m/z calcd. for
C16H18N2O2 ([M + Na]+) 293.1260, found 293.1266; IR (KBr,
neat) v 3104, 1768, 1655, 1615, 1508, 1453, 1271, 1130, 921, 820, 723.
(E)-1-(1-(4-Chlorophenyl)-1H-pyrrol-2-yl)ethan-1-one O-ace-
tyl oxime (1i). The product was isolated by flash chromatography
(E)-1-(1-(4-Nitrophenyl)-1H-pyrrol-2-yl)ethan-1-one O-acetyl
oxime (1o). The product was isolated by flash chromatography
(eluent EtOAc:PE = 1:5) as a yellow solid (437 mg, 76%): mp 103−
1
105 °C; H NMR (400 MHz, CDCl3) δ 8.28−8.23 (m, 2H), 7.47−
7.40 (m, 2H), 6.93 (dd, J = 2.8, 1.6 Hz, 1H), 6.78 (dd, J = 4.0, 1.6 Hz,
1H), 6.37 (dd, J = 3.6, 2.8 Hz, 1H), 2.25 (s, 3H), 1.90 (s, 3H);
13C{1H} NMR (100 MHz, CDCl3) δ 169.0, 154.6, 146.4, 146.1, 128.1,
1
(eluent EtOAc:PE = 1:10) as a yellow oil (437 mg, 79%): H NMR
127.1, 126.3, 124.3, 117.4, 110.6, 19.3, 15.1; HRMS (ESI), m/z calcd.
for C14H13N3O4 ([M + Na]+) 310.0798, found 310.0824; IR (KBr,
neat) v 3072, 1767, 1598, 1513, 1346, 1218, 1187, 1106, 855, 730.
Ethyl (E)-4-(2-(1-(acetoxyimino)ethyl)-1H-pyrrol-1-yl)-
benzoate (1p). The product was isolated by flash chromatography
(400 MHz, CDCl3) δ 7.38 (d, J = 8.4 Hz, 2H), 7.23 (d, J = 8.4 Hz,
2H), 6.87 (t, J = 1.6 Hz, 1H), 6.72 (dd, J = 3.6, 1.2 Hz, 1H), 6.31 (t, J
= 3.4 Hz, 1H), 2.19 (s, 3H), 1.87 (s, 3H); 13C{1H} NMR (100 MHz,
CDCl3) δ 170.4, 154.6, 139.8, 133.0, 129.0, 128.2, 127.3, 127.2, 116.0,
109.6, 19.4, 15.2; HRMS (ESI), m/z calcd. for C14H13ClN2O2 ([M +
Na]+) 299.0558, found 299.0570; IR (KBr, neat) v 3109, 1766, 1666,
1494, 1366, 1229, 1196, 1090, 838, 733.
(E)-1-(1-(2-Chlorophenyl)-1H-pyrrol-2-yl)ethan-1-one O-ace-
tyl oxime (1j). The product was isolated by flash chromatography
(eluent EtOAc:PE = 1:15) as a white solid (387 mg, 70%): mp 54−56
1
(eluent EtOAc:PE = 1:10) as a yellow oil (503 mg, 80%): H NMR
(400 MHz, CDCl3) δ 8.07 (d, J = 8.4 Hz, 2H), 7.32 (d, J = 8.4 Hz,
2H), 6.91 (dd, J = 2.8, 2.0 Hz, 1H), 6.72 (dd, J = 4.0, 1.6 Hz, 1H), 6.31
(t, J = 3.4 Hz, 1H), 4.36 (q, J = 7.2 Hz, 2H), 2.16 (s, 3H), 1.81 (s,
3H), 1.38 (t, J = 7.2 Hz, 3H); 13C{1H} NMR (100 MHz, CDCl3) δ
170.2, 165.6, 154.6, 144.7, 130.3, 128.9, 127.8, 127.1, 125.3, 116.3,
E
J. Org. Chem. XXXX, XXX, XXX−XXX