SYNTHESIS OF CARBAMIC ACID ESTERS
2013
N-(4-Amino-2-methylphenyl)carbamic acid ethyl ester (10). Yield 85%;
white solid; mp 240–242 ꢀC (237–240 ꢀC, lit.[13]) (recryst. heptane). IR (n, cmꢁ1):
3382 (NH2), 1710 (CO), 1265 (N-CO-O). 1H NMR (DMSO): d 10.28 (s, 2H,
NH2), 8.92 (s, 1H, NH), 7.47 (d, J ¼ 9.00 Hz, 1H, ArH), 7.13 (m, 2H, ArH), 4.11
(q, J ¼ 7.30 Hz, 2H, CH2CH3), 2.19 (s, 3H, CH3), 1.21 (t, J ¼ 7.30 Hz, 3H, CH2CH3).
LC=MS (APCIþ) calcd. for C10H14N2O2, m=z: 195 (M þ H)þ.
N-(4-Amino-2-chlorophenyl)carbamic acid methyl ester (11). Yield 84%;
white solid; mp 81–83 ꢀC (recryst. heptane). IR (n, cmꢁ1): 3382 (NH2), 1708 (CO),
1265 (N-CO-O), 1085 (C-Cl). 1H NMR (DMSO): 8.57 (s, 1H, NH), 6.97 (d,
J ¼ 8.40 Hz, 1H, ArH), 6.61 (d, J ¼ 2.30 Hz, 1H, ArH), 6.45 (m, J ¼ 2.30 and
8.40 Hz, 1H, ArH), 5.28 (s, 2H, NH2), 3.57 (s, 3H, OCH3).13C NMR (50 MHz,
DMSO) d 52.1, 113.2, 113.9, 123.2, 129.6, 148.8, 155.9, 158.4. LC=MS (APCIþ)
calcd. for C8H9ClN2O2, m=z: 201 (M þ H)þ and 203 (M þ 2 þ H)þ.
N-(4-Amino-2-chlorophenyl)carbamic acid ethyl ester (12). Yield 84%;
white solid; mp 109–111 ꢀC (recryst. heptane). IR (n, cmꢁ1): 3382 (NH2), 1710
1
(CO), 1264 (N-CO-O), 1085 (C-Cl). H NMR (DMSO): d 8.51 (s, 1H, NH), 6.95
(d, J ¼ 8.40 Hz, 1H, ArH), 6.61 (d, J ¼ 2.60 Hz, 1H, ArH), 6.48 (m, J ¼ 2.60 and
8.40 Hz, 1H, ArH), 5.29 (s, 2H, NH2), 4.02 (q, J ¼ 7.30 Hz, 2H, CH2CH3), 1.21
(t, J ¼ 7.30 Hz, 3H, CH2CH3). 13C NMR (50 MHz, DMSO) d 15.1, 60.5, 113.2,
113.9, 123.2, 129.6, 148.6, 155.4, 158.4. LC=MS (APCIþ) calcd. for C9H11ClN2O2,
m=z: 215 (M þ H)þ and 217 (M þ 2 þ H)þ.
N-(5-Amino-2-methylphenyl)carbamic acid methyl ester (13). Yield
81%; white solid; mp 117–118 ꢀC (recryst. heptane). IR (n, cmꢁ1): 3382 (NH2),
1711 (CO), 1265 (N-CO-O). 1H NMR (DMSO): d 8.42 (s, 1H, NH), 6.77 (d,
J ¼ 8.20 Hz, 1H, ArH), 6.58 (d, J ¼ 2.30 Hz, 1H, ArH), 6.31 (m, J ¼ 2.30 and
8.20 Hz, 1H, ArH), 4.87 (s, 2H, NH2), 3.61 (s, 3H, OCH3), 2.02 (s, 3H, CH3).
13C NMR (50 MHz, DMSO) d 17.22, 51.9, 111.2, 111.6, 130.7, 136.8, 147.1, 155.2,
158.1. LC=MS (APCIþ) calcd. for C9H12N2O2, m=z: 181 (M þ H)þ.
N-(5-Amino-2-methylphenyl)carbamic acid ethyl ester (14). Yield 83%;
white solid; mp 91–92 ꢀC (recryst. heptane). IR (n, cmꢁ1): 3381 (NH2), 1711 (CO),
1
1265 (N-CO-O). H NMR (DMSO): d 8.48 (s, 1H, NH), 6.78 (d, J ¼ 8.20 Hz, 1H,
ArH), 6.61 (d, J ¼ 2.30 Hz, 1H, ArH), 6.21 (m, J ¼ 2.30 and 8.20 Hz, 1H, ArH),
4.82 (s, 2H, NH2), 4.05 (q, J ¼ 7.30 Hz, 2H, CH2CH3), 1.22 (t, J ¼ 7.30 Hz, 3H,
CH2CH3). 13C NMR (50 MHz, DMSO) d 15.1, 17.22, 60.6, 111.7, 112.1, 129.9,
136.3, 147.3, 154.9, 157.6. LC=MS (APCIþ) calcd. for C10H14N2O2, m=z: 195
(M þ H)þ.
N-(5-Amino-2-chlorophenyl)carbamic acid methyl ester (15). Yield 87%;
white solid; mp 117–118 ꢀC (recryst. heptane). IR (n, cmꢁ1): 3382 (NH2), 1712 (CO),
1
1265 (N-CO-O), 1085 (C-Cl). H NMR (DMSO): d 8.67 (s, 1H, NH), 7.03 (d,
J ¼ 8.40 Hz, 1H, ArH), 6.81 (d, J ¼ 2.00 Hz, 1H, ArH), 6.38 (m, J ¼ 2.00 and
8.40 Hz, 1H, ArH), 5.33 (s, 2H, NH2), 3.63 (s, 3H, OCH3).13C NMR (50 MHz,
DMSO) d 52.1, 113.1, 113.8, 123.1, 129.6, 148.5, 155.9, 158.5. LC=MS (APCIþ)
calcd. for C8H9ClN2O2, m=z: 201 (M þ H)þ and 203 (M þ 2 þ H)þ.