8
D. XU ET AL.
1090, 966 cm−1. HRMS (ESI) m/z: [M + H]+ calcd for C14H17N2O2S+ m/z 277.1005;
found, 277.1006.
4.4.4. (S)-1-methyl-N-(1-phenylethyl)-1h-imidazole-2-sulfonamide (4da)
White solid, mp 112–114 °C; Yield: 220 mg, 83%; Specific rotation [α]2D5 = + 91.2 (c = 0.4;
CH2Cl2). 1H NMR (400 MHz, CDCl3) δ 7.26-7.15 (5H, m), 6.97 (2H, m), 6.72 (1H, s), 4.69
(1H, qui, J = 6.4 Hz), 3.65 (3H, s), 1.51 (3H, d, J = 7.2 Hz), 13C NMR (101 MHz, CDCl3)
δ 143.8, 142.4, 128.8, 127.7, 126.5, 124.6, 54.7, 35.3, 23.5. FT-IR (film, cm−1): 3258, 3065,
2974, 2926, 2854, 1459, 1342, 1186, 1148, 302, 632 cm−1. HRMS (ESI) m/z: [M + H]+
calcd for C12H16N3O2S+ m/z 266.0958; found, 266.0960.
4.4.5. Methyl (pyridin-2-ylsulfonyl)-L-Methioninate (4ab)
White solid, mp = 91-92 °C; Yield: 225 mg, 74%; Specific rotation [α]2D5 = + 26.0
(c = 0.25, CH2Cl2). 1H NMR (400 MHz, CDCl3) δ 8.65 (1H, d, J = 4.8 Hz), 7.97 (1H, d,
J = 8.0 Hz), 7.92 (1H, t, J = 8.0 Hz), 7.52-7.47 (1H, m), 5.77 (1H, d, J = 8.8 Hz), 4.45 (1H,
td, J = 8.4 Hz, J = 4.8 Hz), 3.62 (3H, s), 2.65-2.55 (2H, m), 2.18-2.04 (1H, m), 2.07 (3H, s),
2.01-1.91 (1H, m); 13C NMR (101 MHz, CDCl3) δ 171.8, 157.6, 149.6, 138.3, 126.8, 121.9,
77.3, 77.0, 76.7, 55.7, 52.6, 32.8, 29.6, 15.3. FT-IR (film, cm−1): 3257, 2+954, 2919, 1737,
1579, 1427, 1344, 1179. ESI-HRMS [M + H]+ calcd for C11H17N2O4S2 m/z 305.0635;
found, 305.0624.
4.4.6. Methyl (pyridin-2-ylsulfonyl)-L-Valinate (4ac)
Known compound, CAS No. 1384331-68-3. White solid, mp = 109-110 °C, Lit.9 109–109
°C; Yield: 117 mg, 43%; Specific rotation [α]2D5 = + 13.6 (c = 0.25, CH2Cl2), Lit. 9 [α]D =
+17 (c = 1, CH2Cl2, no temperature given by this ref.). 1H NMR (400 MHz, CDCl3) δ 8.62
(1H d, J = 4.4 Hz), 7.95 (1H, d, J = 7.6 Hz), 7.88 (1H, t, J = 7.6 Hz), 7.49-7.43 (1H, m),
5.43 (1H, d, J = 10.0 Hz), 4.14 (1H, dd, J = 10.0, 5.0 Hz), 3.56 (3H, s), 2.16-2.04 (1H, m),
0.99 (3H, d, J = 6.8 Hz), 0.88 (3H, d, J = 6.8 Hz); 13C NMR (101 MHz, CDCl3) δ 171.8,
157.8, 149.6, 138.0, 126.6, 121.7, 77.3, 77.0, 76.7, 62.0, 52.2, 31.7, 18.9, 17.3. ESI-HRMS
[M + H]+ calcd for C11H17N2O4S+ m/z 273.0904; found, 273.0910.
4.4.7. Methyl (pyridin-2-ylsulfonyl)-L-Alaninate (4ad)
White solid, mp = 127-128 °C; Yield: 134 mg, 55%; Specific rotation [α]2D5 = - 2.6
1
(c = 0.15, CH2Cl2). H NMR (400 MHz, CDCl3) δ 8.65 (1H, d, J = 4.0 Hz), 7.96 (1H,
d, J = 8.0 Hz), 7.89 (1H, t, J = 7.8 Hz), 7.50-7.45 (1H, m), 5.68 (1H, d, J = 10.0 Hz), 4.35
(1H, qui, J = 7.6 Hz), 3.62 (3H, s), 1.43 (1H, d, J = 7.2 Hz); 13C NMR (101 MHz, CDCl3)
δ 172.6, 157.9, 149.8, 138.0, 126.7, 121.7, 77.3, 77.0, 76.7, 52.6, 52.4, 20.1. FT-IR (film,
cm−1): 3170, 2994, 2957, 2890, 1471, 1580, 1460, 1435, 1424, 1351, 1213, 1180. ESI-HRMS
[M + H]+ calcd for C9H13N2O4S+ m/z 245.0591; found, 245.0594.
4.4.8. Methyl (pyridin-2-ylsulfonyl)-L-Leucinate (4ae)
Known compound, CAS No. 1384331-70-7. White solid, mp = 80-81 °C, Lit.9 81–83 °C;
Yield: 100 mg, 35%; Specific rotation [α]2D5 = - 5.2 (c = 0.25, CH2Cl2), Lit.9 [α]D = 0
1
(c = 1, CH2Cl2, no temperature given by this ref.). H NMR (400 MHz, CDCl3) δ 8.64
(1H, d, J = 4.8 Hz), 7.97 (1H, d, J = 8.0 Hz), 7.89 (1H, t, J = 7.6 Hz), 7.50-7.44 (1H, m),
5.36 (1H, d, J = 9.6 Hz), 4.34-4.26 (1H, m), 3.56 (3H, s), 1.84 (1H, sep, J = 6.8 Hz), 1.54