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J. R. Davies et al. / Tetrahedron 60 (2004) 3967–3977
(1H, d, J¼6.0 Hz, NH), 7.70 (1H, m, ArH), 7.40 (5H, m,
ArH), 6.98 (2H, m, ArH), 5.43 (1H, d, J¼6.0 Hz, CHNH),
5.26 (2H, s, OCH2Ph), 3.80 (3H, s, OMe), 3.74 (3H, s,
OMe), 2.36 (3H, s, Me); dC (100 MHz; CDCl3) 198.6,
166.6, 164.7, 154.0, 151.4, 135.7, 128.7 (CH), 128.4 (CH),
128.0 (CH), 121.2, 120.2 (CH), 115.3 (CH), 115.0 (CH),
72.1 (CH2), 63.9 (CH), 55.8 (Me), 53.1 (Me), 27.9 (Me);
m/z(EI) 371 (Mþ, 3%), 353 (4), 281 (3), 258 (6), 257 (47),
255 (6), 231 (3), 178 (6), 151 (45), 150 (65), 102 (59), 91
(100), 59 (7).
3.3.9. N-[2-(4-Chlorophenyl)-1-methoxycarbonyl-2-
oxoethyl)thiophene-2-carboxamide 3i. According to the
general procedure, using thiophene-2-carboxamide 1e,
diazo compound 2d and 1,2-dichloromethane as solvent,
the title compound was obtained as a colourless crystalline
solid (36%); mp 100 8C (diethyl ether); (Found: C, 53.2; H,
3.4; N, 4.0. C15H12ClNO4S requires C, 53.3; H, 3.6; N,
4.2%); nmax(KBr)/cm21 3421, 3314, 3109, 3088, 3073,
3037, 2991, 2950, 2843, 1737, 1685, 1644, 1619, 1578,
1532, 1501, 1432, 1358, 1312, 1271, 1224, 1199, 1158,
1086, 1004, 958, 927, 861, 840, 764, 712, 605; dH
(300 MHz; CDCl3) 8.12 (2H, d, J¼8.7 Hz, ArH), 7.64
(1H, dd, J¼1.1, 3.9 Hz, ArH), 7.54 (1H, dd, J¼1.1, 5.0 Hz,
ArH), 7.50 (2H, d, J¼8.7 Hz, ArH), 7.32 (1H, d, J¼7.1 Hz,
NH), 7.11 (1H, dd, 3.9, 5.0, ArH), 6.31 (1H, d, J¼7.1 Hz,
CHNH), 3.75 (3H, s, OMe); dC (75 MHz; CDCl3) 190.7,
167.3, 161.8, 141.7, 137.6, 132.8, 131.6 (CH), 131.4 (CH),
129.7 (CH), 129.6 (CH), 128.2 (CH), 58.5 (CH), 53.5 (Me);
m/z (CI) 340/338 (Mþ, 32/100%), 322/320 (3/7), 308/306
(13/39), 278 (3), 254 (6), 226 (4), 140 (3), 138 (6).
3.3.7. 2-Benzyloxy-N-(1-ethoxycarbonyl-2-oxo-2-phenyl-
ethyl)-5-methoxybenzamide 3g. According to the general
procedure, using amide 1d and diazo compound 2c, the title
compound was obtained as a colourless solid (13%); mp
85–88 8C (diethyl ether); (Found: C, 69.8; H, 5.5; N, 3.0.
C26H25NO6 requires C, 69.8; H, 5.6; N, 3.1%); nmax(KBr)/
cm21 3334, 3088, 3073, 2996, 2976, 2950, 2930, 2899,
2832, 1737, 1690, 1655, 1614, 1598, 1578, 1506, 1486,
1445, 1281, 1224, 1204, 1184, 1158, 1086, 1045, 1025, 979,
948, 902, 815, 769, 743, 687, 645; dH (300 MHz; CDCl3)
9.66 (1H, d, J¼7.1 Hz, NH), 8.34 (2H, d, J¼7.7 Hz, ArH),
7.94 (1H, s, H-6), 7.82 (1H, m, ArH), 7.71 (3H, m, ArH),
7.62–7.48 (4H, m, ArH), 7.19 (2H, m, ArH), 6.59 (1H, d,
J¼7.1 Hz, CHNH), 5.50 (2H, s, OCH2Ph), 4.36 (2H, q,
J¼7.0 Hz, CH2Me), 4.01 (3H, s, OMe), 1.34 (3H, t,
J¼7.0 Hz, CH2Me); dC (75 MHz; CDCl3) 191.2, 166.4,
164.4, 153.5, 151.0, 135.4, 134.1 (CH), 133.8, 129.1 (CH),
128.4 (CH), 128.3 (CH), 127.9 (CH), 127.4 (CH), 121.1,
119.8 (CH), 114.9 (CH), 114.7 (CH), 71.6 (CH2), 61.9
(CH2), 58.8 (CH), 55.4 (Me), 13.5 (Me); m/z (EI) 447 (Mþ,
22%), 429 (53), 401 (16), 357 (20), 340 (26), 339 (44), 297
(20), 258 (28), 257 (100), 239 (57), 212 (28), 151 (50), 150
(85), 91 (94).
3.3.10. N-[1-Methoxycarbonyl-2-(4-methoxycarbonyl-
phenyl)-2-oxoethyl)thiophene-2-carboxamide 3j. Accord-
ing to the general procedure, using thiophene-2-carboxamide
1e, diazo compound 2e and 1,2-dichloromethane as solvent
the title compound was obtained as a colourless crystalline
solid (74%); mp 188–190 8C (diethyl ether); (Found: C, 56.3;
H, 4.1; N, 3.7. C17H15NO6S requires C, 56.5; H, 4.2; N, 3.9%);
n
max(KBr)/cm21 3309, 3249, 3113, 3097, 3067, 3041, 3017,
2957, 2848, 1710, 1690, 1634, 1530, 1502, 1453, 1433, 1421,
1405, 1361, 1317, 1285, 1261, 1237, 1205, 1169, 1113, 1041,
1005, 964, 928, 872; dH (300 MHz; CDCl3) 8.22 (2H, d,
J¼8.7 Hz, ArH), 8.17 (2H, d, J¼8.7 Hz, ArH), 7.65 (1H, dd,
J¼1.1, 3.8 Hz, ArH), 7.54 (1H, dd, J¼1.1, 4.9 Hz, ArH), 7.33
(1H, d, J¼7.3 Hz, NH), 7.11 (1H, dd, J¼3.8, 4.9 Hz, ArH),
6.37 (1H, d, J¼7.3 Hz, CHNH), 3.96 (3H, s, OMe), 3.75 (3H,
s, OMe); dC (75 MHz; CDCl3) 191.7, 167.1, 166.3, 161.8,
137.7, 137.5, 135.4, 131.6 (CH), 130.4 (CH), 129.9 (CH),
129.7 (CH), 128.2 (CH), 58.8 (CH), 53.9 (Me), 53.0 (Me); m/z
(CI) 362 (Mþ, 100%), 344 (7), 330 (25), 278 (3), 176 (3), 163
(8).
3.3.8. N-(1-Methoxycarbonyl-2-oxopropyl)thiophene-2-
carboxamide 3h. According to the general procedure,
using thiophene-2-carboxamide 1e, diazo compound 2a and
1,2-dichloromethane as solvent, the title compound was
obtained as a colourless oil (80%); (Found: C, 49.8; H, 4.5;
N, 5.4. C10H11NO4S requires C, 49.8; H, 4.6; N, 5.8%);
n
max(film)/cm21 3334, 3088, 3073, 2996, 2976, 2950, 2930,
2899, 2832, 1737, 1690, 1655, 1614, 1598, 1578, 1506,
1486, 1445, 1281, 1224, 1204, 1184, 1158, 1086, 1045,
1025, 979, 948, 902, 815, 769, 743, 687, 645; dH (300 MHz;
CDCl3) 7.61 (1H, dd, J¼1.1, 3.8 Hz, ArH), 7.51 (1H, dd,
J¼1.1, 4.9 Hz, ArH), 7.19 (1H, d, J¼6.4 Hz, NH), 7.08 (1H,
dd, J¼3.8, 4.9 Hz, ArH), 5.40 (1H, d, J¼6.4 Hz, CHNH),
3.82 (3H, s, OMe), 2.42 (3H, s, OMe); dC (75 MHz; CDCl3)
198.7, 166.9, 161.7, 137.6, 131.5 (CH), 129.5 (CH), 128.2
(CH), 63.6 (CH), 53.9 (Me), 28.5 (Me); m/z (EI) 241 (Mþ,
20%), 199 (85), 167 (63), 112 (18), 110 (100), 83 (14).
3.3.11. 1-tert-Butyloxycarbonyl-N-(1-methoxycarbonyl-
2-oxopropyl)piperidine-4-carboxamide 3k. According to