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K. C. Majumdar et al.
PAPER
1H NMR (400 MHz, CDCl3): d = 2.45 (s, 3 H), 3.67 (s, 3 H), 4.17
(d, J = 6.6 Hz, 2 H), 4.92 (t, J = 5.8 Hz, 1 H), 6.64 (dd, J = 8.5, 2.4
Hz, 1 H), 6.80 (d, J = 2.4 Hz, 1 H), 7.24 (d, J = 6.3 Hz, 2 H), 7.31
(d, J = 8.7 Hz, 1 H), 7.70 (d, J = 8.0 Hz, 2 H).
13C NMR (125 MHz, CDCl3): d = 21.4, 47.3, 55.4, 113.3, 115.3,
115.4, 127.0, 129.5, 133.2, 136.3, 136.9, 143.4, 158.9.
1H NMR (300 MHz, CDCl3): d = 4.2 (d, J = 6.5 Hz, 2 H), 7.49–7.54
(m, 1 H), 7.60–7.66 (m, 1 H), 7.77–7.83 (m, 2 H), 8.22 (d, J = 7.5
Hz, 2 H), 8.64 (d, J = 2.1 Hz, 1 H), 8.75 (d, J = 1.5 Hz, 1 H).
MS: m/z = 370 [M+], 372 [M + 2].
Anal. Calcd for C13H11BrN2O4S: C, 42.06; H, 2.99; N, 7.55. Found:
C, 42.18; H, 3.21; N, 7.50.
MS: m/z = 369 [M+], 371 [M + 2].
N,N-Bis(2-bromobenzyl)arenesulfonamides 5a–f; General Pro-
cedure
Anal. Calcd for C15H16BrNO3S: C, 48.66; H, 4.36; N, 3.78. Found:
C, 48.61; H, 4.29; N, 3.87.
A mixture of sulfonamides 4a–c (4.13 mmol), 2-bromobenzyl bro-
mides 1a,d (10.33 mmol) and anhyd K2CO3 (3 g) in anhyd MEK (20
mL) in the presence of NaI (cat.) was refluxed for 12 h. The mixture
was cooled and filtered and the solvent was removed. The residual
mass was extracted with CH2Cl2 (3 × 30 mL). The combined
CH2Cl2 extracts were washed with H2O (3 × 30 mL) followed by
brine (1 × 10 mL) and dried (Na2SO4). Removal of CH2Cl2 gave the
crude product, which was purified by chromatography (silica gel,
EtOAc–PE, 1:9) to afford the bromo derivatives 5a–f.
N-(2-Bromo-5-methoxybenzyl)benzenesulfonamide (3b)
White solid; yield: 90%; mp 84–86 °C.
IR (KBr): 3256 cm–1.
1H NMR (400 MHz, CDCl3): d = 3.71 (s, 3 H), 4.20 (d, J = 6.6 Hz,
2 H), 4.96 (t, J = 5.9 Hz, 1 H), 6.64 (dd, J = 8.8, 2.9 Hz, 1 H), 6.80
(d, J = 2.8 Hz, 1 H), 7.30 (d, J = 8.8 Hz, 1 H), 7.45 (t, J = 7.7 Hz, 2
H), 7.53 (t, J = 7.2 Hz, 1 H), 7.81 (d, J = 7.4 Hz, 2 H).
13C NMR (125 MHz, CDCl3): d = 47.4, 55.4, 113.4, 115.4, 115.6,
N,N-Bis(2-bromobenzyl)-4-toluenesulfonamide (5a)
White solid; yield: 95%; mp 133–134 °C.
IR (KBr): 1342, 1160 cm–1.
126.9, 127.2, 128.9, 132.5, 133.2, 136.2, 139.9, 159.0.
MS: m/z = 355 [M+], 357 [M + 2].
Anal. Calcd for C14H14BrNO3S: C, 47.20; H, 3.96; N, 3.93. Found:
C, 47.31; H, 4.11; N, 3.91.
1H NMR (400 MHz, CDCl3): d = 2.45 (s, 3 H), 4.50 (s, 4 H,), 6.99
(t, J = 7.8 Hz, 2 H), 7.13 (t, J = 8.4 Hz, 2 H), 7.33 (t, J = 8.4 Hz, 6
H), 7.73 (d, J = 8.2 Hz, 2 H).
13C NMR (75 MHz, CDCl3): d = 21.4, 52.2, 123.2, 127.1, 127.2,
128.8, 129.7, 130.0, 132.4, 134.7, 136.4, 143.5.
N-(2-Iodobenzyl)-4-toluenesulfonamide (3c)
White solid; yield: 85%; mp 105–107 °C.
IR (KBr): 3260 cm–1.
HRMS: m/z calcd for C21H19Br2NO2S: 529.9335 [M + Na],
531.9381 [M + 2 + Na], 533.9339 [M + 4 + Na]; found: 529.9401
[M + Na], 531.9401 [M + 2 + Na], 533.9401 [M + 4 + Na].
1H NMR (400 MHz, CDCl3): d = 2.43 (s, 3 H), 4.12 (d, J = 6.0 Hz,
2 H), 4.62 (t, J = 5.8 Hz, 1 H), 7.18 (d, J = 6.6 Hz, 2 H), 7.25–7.31
(m, 4 H), 7.75 (d, J = 7.8 Hz, 2 H).
13C NMR (125 MHz, CDCl3): d = 21.5, 51.6, 98.7, 127.1, 128.5,
129.4, 129.6, 129.8, 136.3, 138.6, 139.3, 143.4.
N,N-Bis(2-bromo-5-methoxybenzyl)-4-toluenesulfonamide (5b)
White solid; yield: 92%; mp 110–111 °C.
MS: m/z = 387 [M+].
IR (KBr): 1341, 1163 cm–1.
1H NMR (400 MHz, CDCl3): d = 2.45 (s, 3 H), 3.67 (s, 6 H), 4.45
(s, 4 H,), 6.55 (dd, J = 8.8, 3.0 Hz, 2 H), 6.86 (d, J = 3 Hz, 2 H), 7.21
(d, J = 8.7 Hz, 2 H), 7.34 (d, J = 8.2 Hz, 2 H), 7.77 (d, J = 8.2 Hz, 2
H).
Anal. Calcd for C14H14INO2S: C, 43.42; H, 3.64; N, 3.62. Found: C,
43.54; H, 3.70; N, 3.58.
N-(2-Iodobenzyl)benzenesulfonamide (3d)
White solid; yield: 81%; mp 118–120 °C.
IR (KBr): 3258 cm–1.
1H NMR (400 MHz, CDCl3): d = 4.20 (d, J = 6.2 Hz, 2 H), 4.95 (t,
J = 5.8 Hz, 1 H), 6.92 (t, J = 7.7 Hz, 1 H), 7.26 (t, J = 7.3 Hz, 1 H),
7.45 (t, J = 7.5 Hz, 2 H), 7.53 (t, J = 7.4 Hz, 1 H), 7.71 (d, J = 7.8
Hz, 1 H), 7.81 (t, J = 7.5 Hz, 2 H).
MS: m/z = 567 [M+], 569 [M + 2], 571 [M + 4].
Anal. Calcd for C23H23Br2NO4S: C, 48.52; H, 4.07; N, 2.46. Found:
C, 48.61; H, 4.12; N, 2.55.
N,N-Bis(2-bromobenzyl)benzenesulfonamide (5c)
White solid; yield: 94%; mp 80–82 °C.
13C NMR (125 MHz, CDCl3): d = 51.7, 98.7, 127.0, 128.5, 129.0,
IR (KBr): 1327, 1157 cm–1.
129.6, 130.0, 132.6, 138.3, 139.4, 139.8.
1H NMR (400 MHz, CDCl3): d = 4.54 (s, 4 H,), 6.99 (t, J = 7.6 Hz,
2 H), 7.13 (t, J = 7.4 Hz, 2 H), 7.30 (d, J = 7.6 Hz, 2 H), 7.35 (d,
J = 7.8 Hz, 2 H), 7.51 (t, J = 7.5 Hz, 2 H), 7.59 (t, J = 7.1 Hz, 1 H),
7.84 (d, J = 7.5 Hz, 2 H).
MS: m/z = 373 [M+].
Anal. Calcd for C13H12INO2S: C, 41.84; H, 3.24; N, 3.75. Found: C,
41.71; H, 3.29; N, 3.69.
MS: m/z = 493 [M+], 495 [M + 2], 497 [M + 4].
N-(2-Bromo-5-nitrobenzyl)benzenesulfonamide (3e)
Anal. Calcd for C20H17Br2NO2S: C, 48.51; H, 3.46; N, 2.83. Found:
C, 48.65; H, 3.58; N, 2.73.
A mixture of 4b (0.5 g, 3.19 mmol), 2-bromo-5-nitrobenzyl bro-
mide (1c, 1.41 g, 4.78 mmol) and anhyd K2CO3 (1.32 g, 9.56 mmol)
in anhyd MEK (20 mL) in the presence of NaI (cat.) was refluxed
for 12 h. The mixture was cooled and filtered and the solvent was
removed. The residual mass was extracted with CH2Cl2 (3 × 30
mL). The combined CH2Cl2 extracts were washed with H2O (3 × 30
mL) followed by brine (1 × 10 mL) and dried (Na2SO4). Removal
of CH2Cl2 gave the crude product, which was purified by chroma-
tography (silica gel, EtOAc–PE, 1:9) to afford 3e as a yellow vis-
cous oil; yield: 65%.
N,N-Bis(2-bromo-5-methoxybenzyl)benzenesulfonamide (5d)
White solid; yield: 89%; mp 81–82 °C.
IR (KBr): 1343, 1168 cm–1.
1H NMR (400 MHz, CDCl3): d = 3.67 (s, 6 H), 4.48 (s, 4 H,), 6.56
(dd, J = 8.7, 2.5 Hz, 2 H), 6.87 (d, J = 1.9 Hz, 2 H), 7.23 (t, J = 5.8
Hz, 2 H), 7.54 (t, J = 7.2 Hz, 2 H), 7.61 (t, J = 7.2 Hz, 1 H), 7.88 (d,
J = 7.6 Hz, 2 H).
MS: m/z = 553 [M+], 555 [M + 2], 557 [M + 4].
IR (KBr): 3278, 1307, 1142.
Synthesis 2009, No. 18, 3127–3135 © Thieme Stuttgart · New York