S. Caddick et al. / Tetrahedron 59 (2003) 5417–5423
5421
4.1.12. (6-Chloro-pyridin-3-ylmethyl)-carbamic acid
tert-butyl ester (2l).21 451 mg, 93%; white solid; mp 43–
448C; IR (CH2Cl2) 3353, 2976, 2932, 1701, 1513, 1454,
1H), 7.32 (dt, J¼9.0, 2.5 Hz, 1H), 3.42 (t, J¼6.8 Hz, 2H),
2.58 (t, J¼6.8 Hz, 2H), 1.46 (s, 9H); 13C NMR (75 MHz,
MeOH-d4) d 172.7 (C), 158.8 (C), 139.1 (C), 130.6 (C),
130.3 (CH), 130.1 (CH), 122.9 (CH), 122.8 (CH), 80.6 (C),
38.6 (CH2), 38.2 (CH2), 29.1 (3£CH3); HRMS (ES)
calcd for C14H19N2O3ClNa [MþNa]þ 321.0976, found
321.0980.
1
1365, 1249, 1171, 749, 699 cm21; H NMR (300 MHz,
CDCl3) d 8.22 (d, J¼2.2 Hz, 1H), 7.54 (dd, J¼8.0, 2.2 Hz,
1H), 7.20 (d, J¼8.0 Hz, 1H), 5.40 (br s, 1H), 4.22 (d,
J¼5.3 Hz, 2H), 1.37 (s, 9H); 13C NMR (75 MHz, CDCl3) d
155.6 (C), 149.9 (C), 148.3 (CH), 137.8 (CH), 133.6 (C),
123.8 (CH), 79.6 (C), 41.0 (CH2), 27.9 (3£CH3); MS (EI)
m/z (relative intensity) 243 ([MHþ], 44), 186 ([MHþ2t-
Bu], 64), 169 ([Mþ2Ot-Bu], 26), 152 (59), 107 (35), 84
(76), 57 (84), 49 (100); HRMS (ES) calcd for
C11H16N2O2Cl [MþH]þ 243.0895, found 243.0897.
4.1.18. [2-(2-Chloro-4-fluoro-phenyl)-ethyl]-carbamic
acid tert-butyl ester (2s). 427 mg, 78%; white crystalline
solid; mp 52–538C; IR (CH2Cl2) 3357, 2978, 1692, 1513,
1
1492, 1366, 1250, 1170, 1042, 902, 857 cm21; H NMR
(300 MHz, CDCl3) d 7.19 (dd, JHF¼8.2 Hz, JHH¼6.6 Hz,
1H), 7.11 (dd, JHF¼8.5 Hz, JHH¼2.6 Hz, 1H), 6.92 (app td,
JHF¼8.2 Hz, JHH¼2.6 Hz, 1H), 4.58 (br s, 1H), 3.35 (q,
J¼6.8 Hz, 2H), 2.90 (t, J¼6.8 Hz, 2H), 1.42 (s, 9H); 13C
162.9 and 159.6 (C,
4.1.13. (2-Methoxy-ethyl)-carbamic acid tert-butyl ester
(2m).21 305 mg, 87%; colourless oil. Spectroscopic data
corresponds to that reported in the literature.43
NMR (75 MHz, CDCl3)
d
JCF¼329 Hz), 155.8 (C), 134.7 and 134.5 (C, JCF¼14 Hz),
132.5 (C), 131.8 and 131.7 (CH, JCF¼11 Hz), 117.0 and
116.6 (CH, JCF¼32 Hz), 114.2 and 113.9 (CH, JCF¼28 Hz),
79.3 (C), 40.1 (CH2), 33.2 (CH2), 28.3 (3£CH3); HRMS
(ES) calcd for C13H17NO2FClNa [MþNa]þ 296.0830,
found 296.0829.
4.1.14. Propyl-carbamic acid tert-butyl ester (2n).21
188 mg, 59%; colourless oil. Spectroscopic data corre-
sponds to that reported in the literature.39,44
4.1.15. (5-Amino-1-phenyl-1H-pyrazol-4-ylmethyl)-car-
bamic acid tert-butyl ester (2p). 490 mg, 85%; yellow
solid; mp 86–878C; IR (CH2Cl2) 3328, 2977, 1687, 1626,
4.1.19. (5-Chloro-2-methoxy-benzyl)-carbamic acid tert-
butyl ester (2t). 364 mg, 67%; white solid; mp 80–828C; IR
(CH2Cl2) 3454, 2980, 1705, 1490, 1248, 1170, 908,
1
1498, 1251, 1168, 1012, 859 cm21; H NMR (300 MHz,
CDCl3) d 7.54 (dd, J¼7.8, 1.5 Hz, 2H), 7.45 (td, J¼7.8,
1.7 Hz, 2H), 7.33 (tt, J¼7.8, 1.5 Hz, 1H), 7.29 (s, 1H), 5.09
(br s, 1H), 4.61 (br s, 2H), 4.05 (d, J¼6.2 Hz, 2H), 1.42 (s,
9H); 13C NMR (75 MHz, CDCl3) d 157.2 (C), 144.1 (C),
139.9 (CH), 138.7 (C), 129.3 (2£CH), 127.2 (CH), 123.6
(2£CH), 102.0 (C), 79.6 (C), 33.7 (CH2), 27.8 (3£CH3); MS
(EI) m/z (relative intensity) 288 ([Mþ], 14), 232 ([MHþ2t-
Bu], 36), 187 ([Mþ2CO2t-Bu], 21), 173 ([Mþ2NCO2t-
Bu], 67), 145 ([Mþ2CH2NHCO2t-Bu–NH2], 12), 77 (41),
57 (100); HRMS (ES) calcd for C15H21N4O2 [MþH]þ
289.1664, found 289.1663.
734 cm21
;
1H NMR (300 MHz, CDCl3) d 7.22 (d,
J¼2.5 Hz, 1H), 7.18 (dd, J¼8.7, 2.5 Hz, 1H), 6.75 (d,
J¼8.7 Hz, 1H), 5.02 (br s, 1H [exch]), 4.25 (d, J¼6.0 Hz,
2H), 3.81 (s, 3H), 1.44 (s, 9H); 13C NMR (75 MHz, CDCl3)
d 155.9 (C), 155.8 (C), 128.8 (CH), 128.7 (C), 128.0 (CH),
125.4 (C), 111.3 (CH), 79.4 (C), 55.5 (CH3), 39.9 (CH2),
28.4 (3£CH3); MS (EI) m/z (relative intensity) 271 ([Mþ],
31), 214 ([MHþ2t-Bu], 65), 170 ([Mþ2CO2t-Bu], 81), 155
([Mþ2NHCO2t-Bu], 65), 136 (53), 111 (7) 98 (10), 77 (19),
57 (100); HRMS (ES) calcd for C13H18NO3ClNa [MþNa]þ
294.0867, found 294.0868.
4.1.16. [3-(5-Ethylidene-4-methylene-2-oxo-oxazolidin-
3-yl)-propyl]-carbamic acid tert-butyl ester (2q).
286 mg, 49%; white crystalline solid; mp 101–1038C; IR
(CH2Cl2) 3366, 2930, 1776, 1705, 1488, 1366, 1169, 1012,
4.1.20. (6-Methyl-2-oxo-1,2-dihydro-pyridin-3-
ylmethyl)-carbamic acid tert-butyl ester (2u). 167 mg,
35%; yellow crystalline solid, mp 171–1728C; IR (CH2Cl2)
3364, 2978, 1689, 1648, 1502, 1366, 1168, 1050, 907,
1
925 cm21; H NMR (300 MHz, CDCl3) d 7.21 (dt, J¼7.6,
1
1.4 Hz, 1H), 7.18 (td, J¼7.6, 1.4 Hz, 1H), 7.11 (td, J¼7.6,
1.4 Hz, 1H), 6.98 (app dd, J¼7.6, 1.4 Hz, 1H), 5.08 (br s, 1H
[exch]), 3.90 (t, J¼6.6 Hz, 2H), 3.17 (q, J¼6.6 Hz, 2H),
1.95 (quin., J¼6.6 Hz, 2H), 1.42 (s, 9H); 13C NMR
(75 MHz, CDCl3) d 156.0 (C), 154.9 (C), 142.7 (C), 130.8
(C), 123.9 (CH), 122.6 (CH), 110.1 (CH), 108.2 (CH), 79.3
(C), 39.4 (CH2), 37.2 (CH2), 28.3 (3£CH3), 27.8 (CH3); MS
(EI) m/z (relative intensity) 292 ([Mþ], 25), 236 ([MHþ2t-
Bu], 100), 219 ([Mþ2Ot-Bu], 32), 191 ([Mþ2CO2t-Bu],
23), 175 ([Mþ2H2NCO2t-Bu], 21), 162 ([Mþ2CH2-
HNCO2t-Bu], 30) 148 ([Mþ2(CH2)2HNCO2t-Bu], 25),
135 ([MHþ2(CH2)3HNCO2t-Bu], 24), 121 (16), 102 (19),
77 (18), 57 (100); HRMS (ES) calcd for C15H21N2O4
[MþH]þ 293.1496, found 293.1499.
731 cm21; H NMR (300 MHz, CDCl3) d 12.82 (br s, 1H
[exch]), 7.35 (d, J¼6.9 Hz, 1H), 6.03 (d, J¼6.9 Hz, 1H),
5.54 (t, J¼5.7 Hz, 1H [exch]), 4.14 (d, J¼5.7 Hz, 2H), 2.32
(s, 3H), 1.42 (s, 9H); 13C NMR (75 MHz, CDCl3) d 165.1
(C), 156.0 (C), 144.3 (C), 139.4 (CH), 125.5 (C), 105.8
(CH), 79.1 (C), 40.7 (CH2), 28.4 (3£CH3), 18.8 (q); HRMS
(ES) calcd for C12H19N2O3 [MþH]þ 239.1390, found
239.1393.
4.1.21. [2-(1H-Indol-3-yl)-ethyl]-carbamic acid tert-butyl
ester (2v). 302 mg, 58%; yellow oil. Spectroscopic data
corresponds to that reported in the literature.46
4.1.22. (3-Bromo-4-methoxy-benzyl)-carbamic acid tert-
butyl ester (2w). 284 mg, 45%; white crystalline solid; mp
71–738C; IR (CH2Cl2) 3361, 2976, 1694, 1498, 1366, 1255,
1168, 1054, 1021, 810 cm21; 1H NMR (300 MHz, CDCl3) d
7.44 (s, 1H), 7.16 (d, J¼8.4 Hz, 1H), 6.82 (d, J¼8.4 Hz,
1H), 5.00 (br s, 1H [exch]), 4.20 (d, J¼5.5 Hz, 2H), 3.85 (s,
3H), 1.43 (s, 9H); 13C NMR (75 MHz, CDCl3) d 155.7 (C),
4.1.17. [2-(4-Chloro-phenylcarbamoyl)-ethyl]-carbamic
acid tert-butyl ester (2r).45 299 mg, 50%; pale yellow
solid; mp 150–1518C; IR (CH2Cl2) 3465, 1698, 1528, 1493,
1249, 1173, 1031, 831 cm21; 1H NMR (300 MHz, MeOH-
d4) d 7.60 (dd, J¼9.0, 2.5 Hz, 2H), 7.36 (dt, J¼9.0, 2.5 Hz,