A. S. Demir et al. / Tetrahedron 63 (2007) 461–468
465
reduced pressure. The crude product was then purified by
column chromatography.
(d, J¼8.7 Hz), 123.6 (d, J¼3 Hz), 122.0, 119.7 (d,
J¼13 Hz), 115.6 (d, J¼22 Hz), 112.4, 85.6, 59.7, 57.6,
14.1; Anal. Calcd for C14H14FNO3 (263.26): C, 63.87; H,
5.36; N, 5.32. Found: C, 63.71; H, 5.28; N, 5.12.
4.1.1.1. Ethyl 5-methoxy-2-methyl-1H-pyrrole-3-car-
boxylate 3a. Yield: 170 mg, 93%, white solid (mp¼106–
107 ꢀC), Rf (20% EtOAc/hexane), IR (CHCl3): 3947, 3293,
4.1.1.6. Ethyl 5-ethoxy-2-methyl-1H-pyrrole-3-car-
boxylate 3f. Yield: 169 mg, 86%, white solid (mp¼114–
115 ꢀC), Rf (20% EtOAc/hexane) 0.69, IR (CHCl3): 3932,
3286, 2986, 2369, 2309, 1722, 1439 cmꢁ1 1H NMR
.
(400 MHz, CDCl3): d 7.99 (1H, br s, NH), 5.47 (1H, d,
J¼3.0 Hz, CH), 4.20 (2H, q, J¼7.1 Hz, OCH2Me), 3.71
(3H, s, OMe), 2.35 (3H, s, Me), 1.20 (3H, t, J¼7.1 Hz,
CH2Me); 13C NMR (100 MHz, CDCl3): 165.8, 146.4,
127.8, 109.5, 83.1, 59.3, 57.4, 14.5, 12.7; Anal. Calcd for
C9H13NO3 (183.2): C, 59.00; H, 7.15; N, 7.65. Found: C,
58.88; H, 7.24; N, 7.44.
1
3290, 3294, 2982, 2366, 2334, 1732, 1421 cmꢁ1. H NMR
(400 MHz, CDCl3): d 7.91 (1H, br s, NH), 5.45 (1H, d,
J¼2.9 Hz, CH), 4.18 (2H, q, J¼7.1 Hz, OCH2Me), 3.95
(2H, q, J¼7.1 Hz, CH2Me), 2.35 (3H, s, Me), 1.21 (3H, t,
J¼7.1 Hz, CH2Me), 1.20 (3H, t, J¼7.1 Hz, OCH2Me); 13C
NMR (100 MHz, CDCl3): 165.8, 145.3, 127.5, 109.5, 83.9,
66.2, 59.2, 57.4, 14.5, 12.7; Anal. Calcd for C10H15NO3
(197.23): C, 60.90; H, 7.67; N, 7.10. Found: C, 60.72; H,
7.58; N, 6.81.
4.1.1.2. Ethyl 2-ethyl-5-methoxy-1H-pyrrole-3-car-
boxylate 3b. Yield: 177 mg, 90%, white solid (mp¼70–
71 ꢀC), Rf (20% EtOAc/hexane) 0.70, IR (CHCl3): 3940,
3293, 3285, 2978, 2312, 1732, 1456 cmꢁ1
.
1H NMR
4.1.1.7. Ethyl 5-ethoxy-2-ethyl-1H-pyrrole-3-carbox-
ylate 3g. Yield: 185 mg, 88%, white solid (mp¼115–
116 ꢀC), Rf (20% EtOAc/hexane) 0.65, IR (CHCl3): 3944,
(400 MHz, CDCl3): d 7.63 (1H, br s, NH), 5.44 (1H, d,
J¼2.9 Hz, CH), 4.17 (2H, q, J¼7.0 Hz, OCH2Me), 3.70
(3H, s, OMe), 2.82 (2H, q, J¼7.5 Hz, CH2Me), 1.26 (3H,
t, J¼7.0 Hz, OCH2Me), 1.13 (3H, t, J¼7.5 Hz, CH2Me);
13C NMR (100 MHz, CDCl3): 165.1, 146.3, 133.3, 106.5,
83.3, 59.1, 57.5, 20.1, 14.5, 13.6; Anal. Calcd for
C10H15NO3 (197.23): C, 60.90; H, 7.67; N, 7.10. Found:
C, 60.81; H, 7.55; N, 6.88.
1
3687, 3190, 3049, 2984, 2312, 1691, 1426 cmꢁ1. H NMR
(400 MHz, CDCl3): d 7.61 (1H, br s, NH), 5.41 (1H, d,
J¼3.1 Hz, CH), 4.11 (2H, q, J¼7.1 Hz, OCH2Me), 4.06
(2H, q, J¼7.2 Hz, OCH2Me), 2.81 (2H, q, J¼7.5 Hz,
CH2Me), 1.25 (3H, t, J¼7.2 Hz, OCH2Me), 1.15 (3H,
t, J¼7.5 Hz, CH2Me), 1.02 (3H, t, J¼7.1 Hz, OCH2Me);
13C NMR (100 MHz, CDCl3): 165.0, 145.1, 133.0, 108.7,
84.0, 65.8, 58.9, 20.0, 14.6, 14.5, 13.5; Anal. Calcd for
C11H17NO3 (211.26): C, 62.54; H, 8.11; N, 6.63. Found:
C, 62.43; H, 8.04; N, 6.49.
4.1.1.3. Ethyl 2-isopropyl-5-methoxy-1H-pyrrole-3-
carboxylate 3c. Yield: 187 mg, 89%, white solid
(mp¼121–122 ꢀC), Rf (20% EtOAc/hexane) 0.67, IR
(CHCl3): 3945, 3423, 3189, 3055, 2982, 2930, 2326, 1692,
1
1495 cmꢁ1. H NMR (400 MHz, CDCl3): d 7.81 (1H, br s,
4.1.1.8. Ethyl 5-ethoxy-2-isopropyl-1H-pyrrole-3-car-
boxylate 3h. Yield: 177 mg, 79%, white solid (mp¼101–
103 ꢀC), Rf (20% EtOAc/hexane) 0.67, IR (CHCl3): 3947,
NH), 5.47 (1H, d, J¼2.9 Hz, CH), 4.19 (2H, q, J¼7.1 Hz,
OCH2Me), 3.71 (3H, s, OMe), 3.65 (1H, m, CHMe2), 1.26
(3H, t, J¼7.1 Hz, CH2Me), 1.15 (6H, d, J¼7.0 Hz,
CHMe2); 13C NMR (100 MHz, CDCl3): 165.2, 146.3,
137.7, 107.9, 83.1, 59.3, 57.5, 25.6, 22.0, 14.5; Anal. Calcd
for C11H17NO3 (211.26): C, 62.54; H, 8.11; N, 6.63. Found:
C, 62.42; H, 8.23; N, 6.48.
1
3809, 3291, 3043, 2986, 2301, 1733, 1495 cmꢁ1. H NMR
(400 MHz, CDCl3): d 7.74 (1H, br s, NH), 5.44 (1H, d,
J¼2.4 Hz, CH), 4.17 (2H, q, J¼7.1 Hz, OCH2Me), 3.93
(2H, q, J¼7.1 Hz, OCH2Me), 3.65 (1H, m, CHMe2), 1.29
(3H, t, J¼7.1 Hz, OCH2Me), 1.25 (3H, t, J¼7.1 Hz,
OCH2Me), 1.13 (6H, d, J¼6.9 Hz, CHMe2); 13C NMR
(100 MHz, CDCl3): 165.4, 145.2, 137.4, 107.9, 83.7, 66.1,
59.2, 25.5, 22.0, 14.7, 14.5; Anal. Calcd for C12H19NO3
(225.28): C, 63.98; H, 8.50; N, 6.22. Found: C, 63.86;
H, 8.45; N, 6.11.
4.1.1.4. Ethyl 5-methoxy-2-phenyl-1H-pyrrole-3-car-
boxylate 3d. Yield: 228 mg, 91%, white solid (mp¼129–
131 ꢀC), Rf (20% EtOAc/hexane) 0.81, IR (CHCl3): 3944,
1
3432, 3190, 3032, 2985, 2306, 1722, 1426 cmꢁ1. H NMR
(400 MHz, CDCl3): d 7.77 (1H, br s, NH), 7.21–7.51 (5H,
m, Ph), 5.65 (1H, d, J¼2.9 Hz, CH), 4.13 (2H, q,
J¼7.1 Hz, OCH2Me), 3.78 (3H, s, OMe), 1.19 (3H, t,
J¼7.1 Hz, OCH2Me); 13C NMR (100 MHz, CDCl3):
168.3, 147.8, 133.3, 129.0, 128.7, 128.0, 127.7, 110.5,
85.8, 59.3, 32.8, 14.3; Anal. Calcd for C14H15NO3
(245.27): C, 68.56; H, 6.16; N, 5.71. Found: C, 68.48; H,
6.12; N, 5.58.
4.1.1.9. Ethyl 5-ethoxy-2-phenyl-1H-pyrrole-3-car-
boxylate 3i. Yield: 212 mg, 82%, white solid (mp¼129–
131 ꢀC), Rf (20% EtOAc/hexane) 0.62, IR (CHCl3): 3939,
3295, 3045, 2982, 2369, 1702, 1593 cmꢁ1 1H NMR
.
(400 MHz, CDCl3): d 7.88 (1H, br s, NH), 7.22–7.51 (5H,
m, Ph), 5.68 (1H, d, J¼2.9 Hz, CH), 4.15 (2H, q, J¼7.0 Hz,
OCH2Me), 4.03 (2H, q, J¼7.1 Hz, OCH2Me), 1.34 (3H, t,
J¼7.0 Hz, OCH2Me), 1.21 (3H, t, J¼7.1 Hz, OCH2Me);
13C NMR (100 MHz, CDCl3): 164.9, 147.0, 132.0, 128.8,
128.6, 128.0, 127.7, 110.3, 86.4, 66.4, 59.6, 14.6, 14.2;
Anal. Calcd for C15H17NO3 (259.3): C, 69.48; H, 6.61;
N, 5.40. Found: C, 69.32; H, 6.59; N, 5.11.
4.1.1.5. Ethyl 2-(2-fluorophenyl)-5-methoxy-1H-pyr-
role-3-carboxylate 3e. Yield: 215 mg, 82%, white solid
(mp¼122–123 ꢀC), Rf (20% EtOAc/hexane) 0.78, IR
(CHCl3): 3966, 3701, 3433, 3055, 2988, 2370, 1684,
1
1595 cmꢁ1. H NMR (400 MHz, CDCl3): d 8.06 (1H, br s,
NH), 6.99–7.52 (4H, m, Ph), 5.73 (1H, d, J¼2.9 Hz, CH),
4.11 (2H, q, J¼7.1 Hz, OCH2Me), 3.77 (3H, s, OMe), 1.10
(3H, t, J¼7.1 Hz, OCH2Me); 13C NMR (100 MHz,
CDCl3): 164.6, 160.9 (d, J¼245 Hz), 148.1, 132.0, 129.6
4.1.1.10. Ethyl 5-ethoxy-2-(2-fluorophenyl)-1H-pyr-
role-3-carboxylate 3j. Yield: 221 mg, 80%, white solid
(mp¼104–105 ꢀC), Rf (20% EtOAc/hexane) 0.71, IR
(CHCl3): 3945, 3693, 3416, 3189, 3053, 2985, 1691,