CH2), 1.58 (m, 2H, CH2), 2.36 (m, 2H, CH2), 5.26 (s, 2H, NCH2),
7.06-7.30 (m, 6H, CH and Haryl). 13C NMR (75 MHz, DMSO-d6):
δ 13.6 (CH3), 22.3 (CH2), 25.2 (CH2), 29.5 (CH2), 44.1 (NCH2),
74.7 (C), 125.9 (2 x CHaryl), 126.9 (CHaryl), 128.4 (2 x CHaryl),
132.2 (CH), 137.7 (C), 138.7 (C), 140.3 (C), 172.0 (C=O). IR
(KBr disc, v, cm-1): 2958, 1703, 1629, 1488, 1434, 1352, 1260,
1232, 1097, 743, 721. UV (CH3OH): λmax 206.0 nm (ɛ 10970 M-
1cm-1), 283.0 nm (ɛ 16200 M-1cm-1). HRMS (ESI): m/z 397.9665
(M+H)+; C16H17Br2NO requires 397.9678.
4.2.4.7 1-Butyl-5-(dibromomethylene)-3-hexyl-1H-pyrrol-2-one
(16g)
1
Yield 64% as a yellow oil. H NMR (300 MHz, DMSO-d6): δ
0.90 (m, 6H, 2 x CH3), 1.30 (m, 6H, 3 x CH2), 1.54 (m, 6H, 3 x
CH2), 2.30 (m, 2H, CH2), 3.96 (t, J = 7.5 Hz, 2H, CH2), 6.98 (s,
1H, CH). 13C NMR (75 MHz, DMSO-d6): δ 13.6 (CH3), 13.9
(CH3), 19.7 (CH2), 22.3 (CH2), 25.3 (CH2), 27.3 (CH2), 28.8
(CH2), 31.3 (CH2), 32.0 (CH2), 40.6 (CH2), 73.3 (C), 131.7 (CH),
138.7 (C), 140.6 (C), 171.9 (C=O). IR (film, v, cm-1): 2956, 2858,
1704, 1586, 1456, 1360, 1194, 1134, 1057, 828, 740. UV
(CH3OH): λmax 205.0 nm (ɛ 9270 M-1cm-1), 284.0 nm (ɛ 20630 M-
1cm-1). Mass spectrum: HRMS (ESI): m/z 392.0123 (M+H)+;
C15H23Br2NO requires 392.0148.
4.2.4.3 1,3-Dibutyl-5-(dibromomethylene)-1H-pyrrol-2-one (16c)
1
Yield 56% as a yellow oil. H NMR (300 MHz, DMSO-d6): δ
0.92 (m, 6H, 2 x CH3), 1.35 (m, 4H, 2 x CH2), 1.55 (m, 4H, 2 x
CH2), 2.31 (m, 2H, CH2), 3.96 (t, J = 7.9 Hz, 2H, CH2), 6.99 (s,
1H, CH). 13C NMR (75 MHz, DMSO-d6): δ 13.6 (2 x CH3), 19.7
(CH2), 22.3 (CH2), 25.0 (CH2), 29.5 (CH2), 32.0 (CH2), 40.6
(CH2), 73.3 (C), 131.7 (CH), 138.7 (C), 140.6 (C), 171.9 (C=O).
IR (film, v, cm-1): 2957, 2871, 1701, 1586, 1455, 1361, 1194,
1168, 1134, 1047, 829. UV (CH3OH): λmax 205.0 nm (ɛ 9270 M-
1cm-1), 284.0 nm (ɛ 20630 M-1cm-1). HRMS (ESI): m/z 363.9798
(M+H)+; C13H19Br2NO requires 363.9856.
4.2.5 General protocol 5: α-Bromination of Lactams
A
mixture of lactam 16a-b/e-f (2.28 mmol) and N-
bromosuccinimide (2.80 mmol) in carbon tetrachloride (30 mL)
was heated at reflux for 16 h. The solvent was evaporated in
vacuo and the residue was purified by silica gel chromatography
(1:1 dichloromethane/light petroleum) to afford the α-brominated
lactams 17a-d.
4.2.4.4 3-Butyl-5-(dibromomethylene)-1-p-tolyl-1H-pyrrol-2-one
(16d)
4.2.5.1
4-Bromo-3-(1-bromobutyl)-5-(dibromomethylene)-1-
phenyl-1H-pyrrol-2-one (17a)
1
Yield 92% as a white solid, m.p. 76-78 °C. H NMR (300
1
Yield 74% as a red oil. H NMR (300 MHz, DMSO-d6): δ
MHz, DMSO-d6): δ 0.95 (t, J = 7.1 Hz, 3H, CH3), 1.39 (m, 2H,
CH2), 1.54 (m, 2H, CH2), 2.37 (m, 5H, CH2 and CH3), 7.20 (m,
5H, CH and Haryl). 13C NMR (75 MHz, DMSO-d6): δ 13.7 (CH3),
21.1 (CH3), 22.3 (CH2), 25.2 (CH2), 29.5 (CH2), 75.8 (C), 129.0
(2 x CHaryl), 129.4 (2 x CHaryl), 131.9 (CH), 132.3 (C), 138.3 (C),
138.9 (C), 140.3 (C), 171.8 (C=O). IR (nujol, v, cm-1): 2922,
2855, 1693, 1590, 1514, 1463, 1362, 1190, 1130, 1078, 857, 836,
817, 775, 741, 607. UV (CH3OH): λmax 205.0 nm (ɛ 16690 M-
1cm-1), 303.0 nm (ɛ 14280 M-1cm-1). HRMS (ESI): m/z 397.9615
(M+H)+; C16H17Br2NO requires 397.9677).
0.89-0.92 (m, 3H, CH3), 1.31-1.67 (m, 4H, 2 x CH2), 5.35 (t, J =
7.9 Hz, 1H, CHBr), 7.36-7.58 (m, 5H, Haryl). 13C NMR: δ 14.3
(CH3), 22.2 (CH2), 30.8 (CH2), 43.1 (CHBr), 73.2 (=CBr2), 126.7
(2 x CHaryl), 128.8 (2 x CHaryl), 129.2 (2 x CHaryl), 133.8 (C),
138.4 (C), 143.3 (C), 173.8 (C=O). IR (film, v, cm-1): 3080, 1715,
1594, 1490, 1454, 1380, 1296, 1260, 1139, 809, 746, 692. UV
(CH3OH): λmax 205.0 nm (ɛ 6340 M-1cm-1), 294.0 nm (ɛ 14030
M-1cm-1). HRMS (ESI): m/z 563.7572 (M+Na)+; C15H13Br4NONa
requires 563.7645.
4.2.5.2
(Z)-1-Benzyl-4-bromo-3-(1-bromobutyl)-5-
4.2.4.5 5-(Dibromomethylene)-3-hexyl-1-phenyl-1H-pyrrol-2-one
(16e)
(bromomethylene)-1H-pyrrol-2-one (17b)
1
Yield 92% as a light brown solid, m.p. 80-82 °C. H NMR
(300 MHz, DMSO-d6): δ 0.95 (t, J = 7.2 Hz, 3H, CH3), 1.30-1.50
(m, 2H, CH2), 2.27-2.45 (m, 2H, CH2), 4.95 (t, J = 7.9 Hz, 1H,
CHBr), 5.29 (s, 2H, NCH2), 6.36 (s, 1H, =CHBr), 7.13-7.44 (m,
5H, Haryl). 13C NMR (75 MHz, DMSO-d6): δ 13.1 (CH3), 21.4
(CH2), 37.3 (CH2), 42.8 (CHBr), 44.0 (NCH2), 93.4 (=CHBr),
126.2 (2 x CHaryl), 127.1 (CHaryl), 128.2 (C), 128.5 (2 x CHaryl),
133.2 (C), 137.1 (C), 138.2 (C), 166.8 (C=O). IR (film, v, cm-1):
3083, 3031, 2959, 2930, 2871, 1712, 1622, 1496, 1454, 1434,
1384, 1356, 1333, 1240 1173, 923, 887. UV (CH3OH): λmax
294.0 nm (ɛ 26310 M-1cm-1). HRMS (ESI): m/z 475.8857
(M+H)+; C16H17Br3NO requires 475.8860.
1
Yield 68% as a colourless oil. H NMR (300 MHz, DMSO-
d6): δ 0.89 (m, 3H, CH3), 1.32 (m, 6H, 3 x CH2), 1.57 (m, 2H,
CH2), 2.34 (m, 2H, CH2), 7.16-7.42 (m, 6H, CH and Haryl). 13C
NMR (75 MHz, DMSO-d6): δ 13.9 (CH3), 22.4 (CH2), 25.6
(CH2), 27.3 (CH2), 28.8 (CH2), 31.4 (CH2), 76.2 (C), 128.3
(CHaryl), 128.8 (2 x CHaryl), 129.3 (2 x CHaryl), 132.0 (CH), 135.0
(C), 138.9 (C), 140.2 (C), 171.6 (C=O). IR (KBr disc, v, cm-1):
2925, 2854, 1692, 1598, 1500, 1444, 1191, 1127, 1081, 743,676.
UV (CH3OH): λmax 204.0 nm (ɛ 19690 M-1cm-1), 309.0 nm (ɛ
19590 M-1cm-1). HRMS (ESI): m/z 411.9827 (M+H)+;
C17H19Br2NO requires 411.9833.
4.2.4.6 1-Benzyl-5-(dibromomethylene)-3-hexyl-1H-pyrrol-2-one
(16f)
4.2.5.3 (Z)-4-Bromo-3-(1-bromohexyl)-5-(bromomethylene)-1-
phenyl-1H-pyrrol-2-one (17c)
1
Yield 72% as a yellow oil. H NMR (300 MHz, DMSO-d6): δ
1
90% as a red oil. H NMR (300 MHz, DMSO-d6): δ 0.82-
0.88 (t, J = 7.1 Hz, 3H, CH3), 1.32 (m, 6H, 3 x CH2),1.56 (m, 2H,
CH2), 2.38 (m, 2H, CH2), 5.26 (s, 2H, NCH2), 7.08-7.33 (m, 6H,
CH and Haryl). 13C NMR (75 MHz, DMSO-d6): δ 13.9 (CH3), 22.4
(CH2), 25.5 (CH2), 27.4 (CH2), 27.4 (CH2), 28.8 (CH2), 31.4
(CH2), 44.1(NCH2), 74.8 (C), 125.9 (2 x CHaryl), 126.9 (CHaryl),
128.4 (2 x CHaryl), 132.2 (CH), 137.7 (C), 138.7 (C), 140.3 (C),
172.0 (C=O). IR (film, v, cm-1): 2922, 2854, 1696, 1592, 1495,
1452, 1353, 1144, 1086, 976, 844, 829, 708. UV (CH3OH): λmax
206.0 nm (ɛ 10970 M-1cm-1), 283.0 nm (ɛ 16200 M-1cm-1).
HRMS (ESI): m/z 425.9986 (M+H)+; C18H21Br2NO requires
425.9996.
0.91 (m, 3H, CH3), 1.25-1.62 (m, 6H, 3 x CH2), 2.31-2.46 (m,
2H, CH2) 4.95 (t, J = 7.9 Hz, 1H, CHBr), 6.45 (s, 1H, C=CHBr),
7.29-7.49 (m, 5H, Haryl). 13C NMR (75 MHz, DMSO-d6): δ 13.8
(CH3), 22.2 (CH2), 27.8 (CH2), 30.8 (CH2), 35.3 (CH2), 43.1
(CHBr), 94.2 (=CHBr), 128.7 (2 x CHaryl), 128.8 (2 x CHaryl),
129.2 (CHaryl), 133.1 (C), 133.8 (C), 138.4 (C), 146.9 (C), 166.5
(C=O). IR (film, v, cm-1): 3084, 1716, 1595, 1499, 1454, 1382,
1299, 1263, 1139, 809, 746, 692. UV (CH3OH): λmax 205.0 nm
(ɛ 6340 M-1cm-1), 294.0 nm (ɛ 14030 M-1cm-1). HRMS (ESI): m/z
513.8825 (M+Na)+; C17H18Br3NONa requires 513.8810.