PAPER
O-tert-Butoxycarbonylation of Phenols
MS (EI): m/z = 244 [M]+.
1453
13C NMR (75 MHz, CDCl3): d = 166.7, 155.1, 151.6, 131.6, 128.0,
121.7, 84.6, 52.7, 28.1.
4-[(tert-Butoxycarbonyloxy)methyl]-1,2-(methylenedioxy)ben-
zene (6)
Method B; clear liquid; yield: 95%.
MS (EI): m/z = 252 [M]+.
Anal. Calcd for C13H16O5: C, 61.90; H, 6.39. Found: C, 61.87; H,
6.43.
IR (CCl4): 2980, 2900, 1743, 1504, 1492, 1447, 1370, 1284, 1161,
1100, 1085, 1040, 932, 856 cm –1
.
1-(tert-Butoxycarbonyloxy)-2-nitrobenzene (2o)
Method B; light-green-colored liquid; yield: 98%.
1H NMR (300 MHz, CDCl3): d = 6.82–6.83 (m, 2 H), 6.75–6.68 (m,
1 H), 5.94 (s, 2 H), 4.97 (s, 2 H), 1.48 (s, 9 H).
13C NMR (75 MHz; CDCl3): d = 153.3, 147.6, 129.3, 122.2, 108.9,
108.0, 101.0, 82.0, 68.5, 27.6.
IR(KBr): 2983, 2934, 1887, 1768, 1597, 1523, 1354, 1285, 1258,
1146, 1090, 1008, 856, 768 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.13–8.11 (m, 1 H), 7.69–7.64 (m,
1 H), 7.43–7.38 (m, 1 H), 7.33–7.31 (m, 1 H), 1.57 (s, 9 H).
MS (EI): m/z = 252 [M]+.
13C NMR (75 MHz, CDCl3): d = 144.9, 136.8, 135.4, 127.1, 126.4,
125.6, 85.7, 28.1.
Anal. Calcd for C13H16O5: C, 61.90; H, 6.39. Found: C, 61.88; H,
6.42.
MS (EI): m/z = 239 [M]+.
Ethyl (S)-2-(Acetylamino)-3-[4-(tert-butoxycarbonyloxy)phe-
nyl]propanoate (8b)
Method B; white solid; yield: 92%; mp 77 °C.
Anal. Calcd for C11H13NO5: C, 55.23; H, 5.48; N, 5.86. Found: C,
55.20; H, 5.52; N, 5.47.
[a]D30 –1.1 (c 2.5, MeOH).
2-(tert-Butoxycarbonyloxy)phenol (2p)
Method A; colorless oil; yield: 86%.
IR (KBr): 3314, 3251, 3068, 2980, 1759, 1733, 1645, 1553, 1553,
1512, 1455, 1371, 1272, 1218, 1151, 1020 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.07 (d, J = 8.52 Hz, 2 H), 7.01 (d,
J = 8.51 Hz, 2 H), 6.50 (br s, 1 H), 4.73–4.76 (m, 1 H), 4.07 (q,
J = 7.05 Hz, 2 H), 3.00 (t, J = 5.5 Hz, 2 H), 1.88 (s, 3 H), 1.47 (s, 9
H), 1.14 (t, J = 7.1 Hz, 3 H).
13C NMR (75 MHz, CDCl3): d = 172.2, 170.6, 152.3, 150.6, 134.2,
130.7, 121.7, 116.0, 84.0, 62.0, 53.9, 37.7, 28.1, 23.3, 14.5.
MS (APCI): m/z = 352 [M + 1]+.
IR (CCl4): 3426, 2981, 2935, 1762, 1602, 1511, 1371, 1297, 1147,
1096 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.05–7.27 (m, 3 H), 6.86–6.96 (m,
1 H), 5.85 (br s, 1 H, D2O exchangeable), 1.55 (s, 9 H).
13C NMR (75 MHz, CDCl3): d = 147.7, 127.4, 127.0, 123.7, 122.7,
121.3, 118.0, 85.0, 28.2.
MS (EI): m/z = 210 [M]+.
Anal. Calcd for C11H14O4: C, 62.85; H, 6.71. Found: C, 62.80; H,
6.75.
Anal. Calcd for C18H25NO6: C, 61.52; H, 7.17; N, 3.99. Found: C,
61.50; H, 7.20; N, 4.01.
1,4-Bis(tert-butoxycarbonyloxy)benzene
Method B; clear syrup; yield: 84%.
Ethyl (S)-2-(Benzoylamino)-3-[4-(tert-butoxycarbonyloxy)phe-
nyl]propanoate (8c)
Method B; white solid; yield: 74%; mp 108–110 °C.
[a]D30 –1.8 (c 2.0, MeOH).
IR (CCl4): 2978, 2930, 1768, 1600, 1496, 1457, 1367, 1254, 1180,
1169, 1108, 895 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.18–7.25 (m, 4 H), 1.55 (s, 18 H).
13C NMR (75 MHz, CDCl3): d = 150.8, 142.7, 126.4, 123.1, 83.6,
27.6.
IR (KBr): 3370, 2987, 1754, 1645, 1514, 1367, 1274, 1149, 1014
cm–1.
1H NMR (300 MHz, CDCl3): d = 7.73 (d, J = 7.21 Hz, 2 H), 7.31–
7.52 (m, 3 H), 7.07–7.16 (m, 4 H), 6.69 (br s, 1 H), 5.03–5.07 (m, 1
H), 4.20 (q, J = 7.03 Hz, 2 H), 3.25–3.26 (m, 2 H), 1.54 (s, 9 H),
1.26 (t, J = 7.07 Hz, 3 H).
13C NMR (75 MHz, CDCl3): d = 172.0, 167.4, 150.8, 134.0, 132.3,
130.9, 129.2, 127.6, 121.8, 62.3, 54.1, 37.8, 28.2, 14.7.
MS (APCI): m/z = 413 [M + 1]+.
MS (EI): m/z = 310 [M]+.
2-(tert-Butoxycarbonyloxy)-1,3,5-trimethylbenzene (2q)
Method B; clear liquid; yield: 81%.
IR (CCl4): 2980, 1755, 1486, 1276 cm–1.
1H NMR (300 MHz, CDCl3): d = 6.83 (s, 2 H), 2.23 (s, 3 H), 2.19
(s, 6 H), 1.54 (s, 9 H).
13C NMR (75 MHz, CDCl3): d = 152.1, 146.8, 135.8, 129.8, 129.6,
83.4, 28.2, 21.3, 16.6.
Anal. Calcd for C23H27NO6: C, 66.81; H, 6.58; N, 3.39. Found: C,
66.80; H, 6.60; N, 3.41.
MS (EI): m/z = 236 [M]+.
1-(tert-Butoxycarbonylsulfanyl)-4-nitrobenzene (12b)
Pale yellow color solid; yield: 95%; mp 93–95 °C.
Anal. Calcd for C14H20O3: C, 71.16; H, 8.53. Found: C, 71.14; H,
8.57.
IR (KBr): 2990, 2841, 1730, 1596, 1514, 1477, 1371, 1343, 1198,
1005, 842 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.22 (d, J = 8.9 Hz, 2 H), 7.44 (d,
J = 8.9 Hz, 2 H), 1.53 (s, 9 H).
2-(tert-Butoxycarbonyloxy)naphthalene (4b)
Method B; white solid; yield: 98%; mp 69–70 °C.
13C NMR (300 MHz, CDCl3): d = 166.1, 148.5, 138.1, 135.0, 124.3,
IR (KBr): 3413, 3000, 2930, 1750, 1629, 1600, 1510, 1465, 1370,
1283, 1261, 1240, 1144, 1012, 957, 871 cm–1.
1H NMR (300 MHz, CDCl3): d = 8.00–8.06 (m, 3 H), 7.88–7.89 (m,
1 H), 7.63–7.71 (m, 2 H), 7.43–7.57 (m, 1 H), 1.81 (s, 9 H).
13C NMR (75 MHz, CDCl3): d = 152.6, 149.3, 134.3, 132.0, 130.0,
128.3, 126.3, 121.5, 118.8, 84.2, 28.3.
87.5, 28.7.
MS (EI): m/z = 255 [M]+.
Anal. Calcd. for C11H13NO4S: C, 51.75; H, 5.13; N, 5.49; S, 12.56.
Found: C, 51.73; H, 5.15; N, 5.48; S, 12.56.
Synthesis 2008, No. 9, 1448–1454 © Thieme Stuttgart · New York