The Journal of Organic Chemistry
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dried over anhyd Na2SO4, and concentrated. The crude product was
purified by column chromatography using silica gel (100−200).
Elution with hexanes followed by 5% EtOAc−hexanes yielded the off-
white pure solid compound.
atmosphere (1 atm, balloon) for 2 h. The reaction mixture was
filtered over a Celite bed, and the bed was repeatedly washed with
THF. Upon evaporating the THF under reduced pressure from the
combined filtrate, the desired product was obtained as an white/off-
white solid in quantitative yield. The product was absolutely pure and
was used as such for the next reaction.
4-Nitrophenyl 3,4-Bis(hexyloxy)benzoate (3a). Rf = 0.55 (20%
EtOAc−hexanes); white solid, mp: 95−97 °C; yield: 0.63 g (62%). IR
(KBr pellet): νmax in cm−1 2926, 2856, 2364, 1724, 1595, 1519, 1467,
1430, 1351, 1284, 1220, 1144, 1079, 953, 753; 1H NMR (CDCl3, 200
MHz): δ 8.32 (d, 2H, J = 9.0 Hz, Ar), 7.82 (dd, 1H, J = 2 Hz, J = 8.4
Hz, Ar), 7.64 (d, 1H, J = 1.8 Hz, Ar), 7.40 (d, 2H, J = 9.2 Hz), 6.94 (d,
1H, J = 8.6 Hz, Ar), 4.08 (m, 4H, J = 6.4 Hz, 2 × OCH2), 0.91−1.88
(m, 22H, 8 × CH2, 2 × CH3). 13C NMR (CDCl3, 100 MHz): 164.1,
156.0, 154.4, 148.8, 145.3, 125.2, 124.7, 122.7, 120.4, 114.7, 112, 69.4,
69.1, 31.5, 29.1, 29.0, 25.7, 22.6, 14.0. MS (FAB+): m/z for
C25H34NO6 [M + 1], Calcd: 444.2. Found: 444.3. Anal. Calcd for
C25H33NO6: C, 67.7; H, 7.5; N, 3.16. Found: C, 68.1; H, 7.7; N, 3.3.
4-Nitrophenyl 3,4-Bis(heptyloxy)benzoate (3b). Rf = 0.55 (20%
EtOAc−hexanes); white solid, mp: 96−98 °C; yield: 0.7 g (65%). IR
(KBr pellet): νmax in cm−1 2924, 2849, 1723, 1595, 1519, 1467, 1429,
1352, 1283, 1220, 1144, 1079, 958, 753. 1H NMR (CDCl3, 400 MHz):
δ 8.32 (d, 2H, J = 8.8 Hz, Ar), 7.82 (d, 1H, J = 8.4 Hz, Ar), 7.64 (s,
1H, Ar), 7.4 (d, 2H, J = 8.8 Hz), 6.94 (d, 1H, J = 8.4 Hz, Ar), 4.08 (m,
4H, J = 6.4 Hz, 2 × OCH2), 0.86−1.86 (m, 26H, 10 × CH2, 2 × CH3).
13C NMR (CDCl3, 100 MHz): 164.1, 156, 154.4, 148.8, 145.2, 125.2,
124.7, 122.7, 120.4, 114.5, 111.9, 69.4, 69.1, 31.8, 29.1, 29, 25.94,
25.90, 22.6, 14.1. MS (FAB+): m/z for C27H37NO6, Calcd: 471.26.
Found: 471.2. Anal. Calcd for C27H37NO6: C, 68.77; H, 7.91; N, 2.92.
Found: C, 68.8; H, 7.6; N, 3.1.
4-Aminophenyl 3,4-Bis(hexyloxy)benzoate (4a). Rf = 0.28 (30%
EtOAc−hexanes); off-white solid, mp: 93−94 °C. IR (KBr pellet):
νmax in cm−1 3349, 2931, 2858, 2365, 1727, 1707, 1597, 1510, 1429,
1
1353, 1277, 1191, 1141, 1089, 960, 757, 653. H NMR (CDCl3, 400
MHz): δ 7.79 (dd, 1H, J = 2 Hz, J = 8.4 Hz, Ar), 7.65 (d, 1H, J = 2 Hz,
Ar), 6.98 (dd, 2H, J = 2.1 Hz, J = 8.7 Hz, Ar), 6.92 (d, 1H, J = 8.5 Hz,
Ar), 6.71 (dd, 2H, J = 2.2 Hz, J = 8.7 Hz, Ar), 4.07 (q, 4H, J = 6.5 Hz,
2 × OCH2), 3.64 (brs, 2H, NH2), 0.85−1.85 (m, 22H, 8 × CH2, 2 ×
CH3). 13C NMR (CDCl3, 400 MHz): 165.6, 153.6, 148.6, 144.1,
143.3, 124.2, 122.4, 121.9, 115.7, 114.6, 111.9, 69.3, 69.1, 31.6, 29.1,
29.0, 25.67, 25.65, 22.6, 14.0. MS (FAB +): m/z for C25H36NO4 [M +
1], Calcd: 414.3. Found: 414.1. Anal. Calcd for C25H35NO4: C, 72.61;
H, 8.53; N, 3.39. Found: C, 72.5; H, 8.6; N, 3.5.
4-Aminophenyl 3,4-Bis(heptyloxy)benzoate (4b). Rf = 0.28 (30%
EtOAc−hexanes); off-white solid, mp: 81−82 °C. IR (KBr pellet):
νmax in cm−1 3349, 2926, 2856, 2365, 1726, 1706, 1598, 1509, 1429,
1291, 1190, 1011, 960, 757, 652. 1H NMR (CDCl3, 400 MHz): δ 7.79
(dd, 1H, J = 2 Hz, 8.4 Hz, Ar), 7.65 (d, 1H, J = 2 Hz, Ar), 6.98 (d, 2H,
J = 12.0 Hz, Hz, Ar), 6.91 (d, 1H, J = 8.5 Hz, Ar), 6.71 (d, 2H, J = 12.2
Hz, Ar), 4.07 (q, 4H, J = 6.48 Hz, 2 × OCH2), 3.64 (brs, 2H, NH2),
0.87−1.88 (m, 26H, 10 × CH2, 2 × CH3). 13C NMR (CDCl3, 100
MHz): 165.6, 153.6, 148.6, 144.1, 143.3, 124.2, 122.4, 121.9, 115.7,
114.6, 111.9, 69.3, 69.1, 31.8, 29.2, 29.1, 26, 25.9, 22.6, 14.0. MS (FAB
+): m/z for C27H39NO4, Calcd: 441.3. Found: 441. Anal. Calcd for
C27H39NO4: C, 73.43; H, 8.9; N, 3.17. Found: C, 73.5; H, 8.71; N,
3.21.
4-Nitrophenyl 3,4-Bis(octyloxy)benzoate (3c). Rf = 0.56 (20%
EtOAc−hexanes); white solid, mp: 97−99 °C; yield: 0.81 g (70%). IR
(KBr pellet): νmax in cm−1 2924, 2850, 1723, 1595, 1519, 1430, 1352,
1
1285, 1220, 1144, 1079, 967, 753. H NMR (CDCl3, 200 MHz): δ
8.34 (d, 2H, J = 9 Hz, Ar), 7.81 (dd, 1H, J = 2.0 Hz, J = 8.6 Hz, Ar),
7.64 (d, 1H, J = 2 Hz, Ar), 7.41 (d, 2H, J = 9.2 Hz), 6.94 (d, 1H, J =
8.6 Hz, Ar), 4.08 (q, 4H, J = 6.4 Hz, 2 × OCH2), 0.86−1.91 (m, 30H,
12 × CH2, 2 × CH3). 13C NMR (CDCl3, 100 MHz): 164.1, 156.0,
154.4, 148.8, 145.3, 125.2, 124.7, 122.7, 120.4, 114.7, 112.0, 69.5, 69.1,
31.8, 29.3, 29.2, 29.16, 29, 25.99, 25.95, 22.7, 14.1. MS (FAB+): m/z
for C29H41NO6, Calcd: 499.3. Found: 499. Anal. Calcd for
C29H41NO6: C, 69.71; H, 8.27; N, 2.8. Found: C, 69.5; H, 8.1; N, 2.9.
4-Nitrophenyl 3,4-Bis(decyloxy)benzoate 3d). Rf = 0.56 (20%
EtOAc−hexanes); white solid, mp: 98−99 °C; yield: 0.92 g (72%). IR
(KBr pellet): νmax in cm−1 2919, 2848, 1723, 1595, 1519, 1429, 1353,
4-Aminophenyl 3,4-Bis(octyloxy)benzoate (4c). Rf = 0.27 (30%
EtOAc−hexanes); off-white solid, mp: 74−75 °C. IR (KBr pellet):
νmax in cm−1 2923, 2851, 1730, 1696, 1598, 1512, 1428, 1279, 1090,
1014, 864, 754, 512. 1H NMR (CDCl3, 400 MHz): δ 7.79 (dd, 1H, J =
4 Hz, J = 8 Hz, Ar), 7.65 (d, 1H, J = 4 Hz, Ar), 6.98 (d, 1H, J = 12 Hz,
Ar), 6.91 (d, 1H, J = 12 Hz, Ar), 6.70 (d, 2H, J = 12 Hz, Ar), 4.08 (q,
4H, J = 8 Hz, 2 × OCH2), 3.64 (s, 2H, NH2), 0.87−1.89 (m, 30H, 12
× CH2, 2 × CH3). 13C NMR (CDCl3, 100 MHz): 165.6, 153.6, 148.6,
144.1, 143.3, 124.2, 122.4, 121.9, 115.7, 114.7, 112.0, 69.3, 69.1, 31.8,
29.2, 29.1, 25.94, 25.9, 22.6, 14.1. MS (FAB+): m/z for C29H44NO4
[M + 1], Calcd: 470.4. Found: 470.2. Anal. Calcd for C29H43NO4: C,
74.16; H, 9.23; N, 2.98. Found: C, 74.3; H, 9.5; N, 3.1.
4-Aminophenyl 3,4-Bis(decyloxy)benzoate (4d). Rf = 0.29 (30%
EtOAc−hexanes); off-white solid, mp: 73−74 °C. IR (KBr pellet):
νmax in cm−1 3342, 2921, 2851, 1728, 1695, 1596, 1512, 1428, 1278,
1085, 1013, 760, 512. 1H NMR (CDCl3, 400 MHz): δ 7.79 (dd, 1H, J
= 4 Hz, J = 8 Hz, Ar), 7.65 (d, 1H, J = 4 Hz, Ar), 6.98 (d, 2H, J = 12
Hz, Ar), 6.91 (d, 1H, J = 12 Hz, Ar), 6.70 (d, 2H, J = 12 Hz, Ar), 4.08
(q, 4H, J = 8 Hz, 2 × OCH2), 3.64 (brs, 2H, NH2), 0.86−1.89 (m,
38H, 16 × CH2, 2 × CH3). 13C NMR (CDCl3, 100 MHz): 165.6,
153.7, 148.6, 144.1, 143.3, 124.2, 122.4, 121.9, 115.7, 114.7, 112.0,
69.4, 69.1, 31.9, 29.6, 29.56, 29.4, 29.3, 29.2, 29.1, 26, 25.96, 22.67,
14.1. MS (FAB+): m/z for C33H52NO4 [M + 1], Calcd: 526.4. Found:
526. Anal. Calcd for C33H51NO4: C, 75.39; H, 9.78; N, 2.66. Found: C,
75.6; H, 9.9; N, 2.8.
4-Aminophenyl 3,4-Bis(dodecyloxy)benzoate (4e). Rf = 0.28 (30%
EtOAc−hexanes); off-white solid, mp: 70−71 °C. IR (KBr pellet):
νmax in cm−1 2920, 2850, 1716, 1594, 1515, 1471, 1275, 1079, 1006,
862, 762, 514. 1H NMR (CDCl3, 200 MHz): δ 7.79 (dd, 1H, J = 2 Hz,
8.4 Hz, Ar), 7.65 (d, 1H, J = 2 Hz, Ar), 6.89−7 (m, 3H, Ar), 6.71 (d,
2H, J = 8.8 Hz, Ar), 4.02 −4.11 (m, 4H, 2 × OCH2), 3.64 (bs, 2H,
NH2), 0.85−1.84 (m, 46H, 20 × CH2, 2 × CH3). 13C NMR (CDCl3,
100 MHz): 165.6, 153.7, 148.6, 144.1, 143.3, 124.2, 122.4, 121.9,
115.7, 114.7, 112.0, 69.4, 69.1, 31.9, 29.68, 29.65, 29.6, 29.40, 29.35,
29.2, 29.1, 26.0, 25.96, 22.7, 14.1. MS (FAB+): m/z for C37H59NO4,
Calcd: 581.44. Found: 581.3. Anal. Calcd for C37H59NO4: C, 76.37; H,
10.22; N, 2.41. Found: C, 76.5; H, 10.4; N, 2.5.
1
1283, 1221, 1145, 1080, 949, 753. H NMR (CDCl3, 200 MHz): δ
8.32 (d, 2H, J = 9 Hz, Ar), 7.81 (dd, 1H, J = 1.8 Hz, J = 8.4 Hz, Ar),
7.64 (d, 1H, J = 2 Hz, Ar), 7.4 (d, 2H, J = 9.2 Hz), 6.94 (d, 1H, J = 8.6
Hz, Ar), 4.08 (q, 4H, J = 6.4 Hz, 2 × OCH2), 0.85−1.87 (m, 38H, 16
× CH2, 2 × CH3). 13C NMR (CDCl3, 100 MHz): 164.1, 156.0, 154.5,
148.8, 145.3, 125.2, 124.7, 122.7, 120.4, 114.7, 112, 69.5, 69.1, 31.9,
29.59, 29.56, 29.4, 29.36, 29.33, 29.2, 29, 26.0, 25.96, 22.7, 14.1; MS
(FAB+): m/z for C33H50NO6 [M + 1], Calcd: 556.4. Found: 556.5.
Anal. Calcd for C33H49NO6: C, 71.32; H, 8.89; N, 2.52. Found: C,
71.4; H, 8.6; N, 2.8.
4-Nitrophenyl 3,4-Bis(dodecyloxy)benzoate (3e). Rf = 0.58 (20%
EtOAc−hexanes); white solid, mp: 100−102 °C; yield: 0.87 g, (62%).
IR (KBr pellet): νmax in cm−1 2918, 2848, 1724, 1593, 1519, 1430,
1353, 1284, 1220, 1145, 1080, 949, 753. 1H NMR (CDCl3, 200 MHz):
δ 8.32 (d, 2H, J = 9 Hz, Ar), 7.82 (dd, 1H, J = 2 Hz, J = 8 Hz, Ar), 7.64
(d, 1H, J = 2 Hz, Ar), 7.4 (d, 2H, J = 8 Hz), 6.94 (d, 1H, J = 8 Hz, Ar),
4.1 (q, 4H, J = 6 Hz, 2 × OCH2), 0.85−1.85 (m, 46H, 20 × CH2, 2 ×
CH3). 13C NMR (CDCl3, 100 MHz): 164.1, 156.0, 154.5, 148.9,
145.3, 125.2, 124.7, 122.7, 120.4, 114.7, 112.0, 69.5, 69.1, 31.9, 29.7,
29.66, 29.59, 29.56, 29.38, 29.36, 29.33, 29.2, 29.0, 26.0, 25.96, 22.7,
14.1; MS (FAB+): m/z for C37H58NO6 [M + 1], Calcd: 612.4. Found:
612.4. Anal. Calcd for C37H57NO6: C, 72.63; H, 9.39; N, 2.29. Found:
C, 72.4; H, 9.41; N, 2.41.
General Procedure for the Synthesis of 4-Aminophenyl 3,4-
Bis(alkoxy)benzoate (4a−e). To a solution of nitro compound (1
mmol) (3a−e) in dry THF (20 mL) was added 10% Pd−C (5 wt %);
the solution was degassed and stirred at RT under hydrogen
M
dx.doi.org/10.1021/jo302332u | J. Org. Chem. XXXX, XXX, XXX−XXX