V. Diemer, H. Chaumeil, A. Defoin, A. Fort, A. Boeglin, C. Carré
7:3) by using procedure G. Sublimation was possible (170 °C,
FULL PAPER
IR (KBr): ν = 879, 889, 1017, 1058, 1075, 1084, 1119, 1168, 1210,
˜
1
1224, 1263, 1361, 1370, 1394, 1413, 1459, 1480, 1582, 2871, 2935,
2966, 3016 cm–1. C24H35NO (353.55): calcd. C 81.53, H 9.98, N
3.96; found C 81.68, H 9.91, N 4.04.
1 Torr). M.p. 238 °C. H NMR (400 MHz, CDCl3): δ = 1.15 (d, J
= 7.0 Hz, 12 H), 1.45 (s, 18 H), 2.69 (hept, J = 7.0 Hz, 2 H), 5.31
(s, 1 H), 6.86 (s, 2 H), 8.43 (s, 2 H) ppm. 13C NMR (100.6 MHz,
CDCl3): δ = 24.1, 28.9, 30.6, 34.5, 125.2, 128.3, 135.8, 141.9, 144.8,
4-(3,5-Di-tert-butyl-4-methoxyphenyl)-3,5-diisopropylpyridine (5e):
Compound 5e (1.69 g, 94%) was obtained as colourless crystals
from 9e (1.85 g, 4.72 mmol) after chromatography by using pro-
cedure F. Sublimation was possible (160 °C, 1 Torr). M.p. 132–
148.7, 153.1 ppm. IR (KBr): ν = 885, 890, 1044, 1058, 1117, 1133,
˜
1238, 1256, 1283, 1361, 1387, 1431, 1442, 1458, 2864, 2923, 2954,
2964, 3247 cm–1. C25H37NO (367.58): calcd. C 81.69, H 10.15, N
3.81; found C 81.46, H 10.16, N 3.98.
1
133 °C. H NMR (400 MHz, CDCl3): δ = 1.15 (d, J = 7.0 Hz, 12
4-(3,5-Di-tert-butyl-4-hydroxyphenyl)-1-methylpyridinium Iodide
(18a): Compound 18a (425 mg, 100%) was obtained as colourless
crystals from biaryl 17a (287 mg, 1 mmol) by using procedure H.
1H NMR (400 MHz, CD3OD): δ = 1.52 (s, 18 H), 4.35 (s, 3 H),
7.78 (s, 2 H), 8.28 (d, J = 7.0 Hz, 2 H), 8.73 (d, J = 7.0 Hz, 2
H) ppm. 13C NMR (100.6 MHz, CD3OD): δ = 30.4, 35.8, 47.7,
124.6, 125.8, 126.3, 140.3, 146.0, 158.2, 160.1 ppm.
H), 1.43 (s, 18 H), 2.68 (hept, J = 7.0 Hz, 2 H), 3.75 (s, 3 H), 6.94
(s, 2 H), 8.44 (s, 2 H) ppm. 13C NMR (100.6 MHz, CDCl3): δ =
24.0, 28.9, 32.3, 35.9, 64.4, 126.9, 131.7, 141.4, 143.4, 145.1, 148.1,
158.6 ppm. IR (KBr): ν = 884, 1015, 1063, 1118, 1208, 1223, 1257,
˜
1361, 1411, 1445, 1462, 2866, 2924, 2962 cm–1. C26H38NO (381.61):
calcd. C 81.84, H 10.30, N 3.67; found C 81.74, H 10.27, N 3.83.
2,6-Di-tert-butyl-4-(pyridin-4-yl)phenol (17a): Compound 17a
(774 mg, 65%) was obtained as colourless crystals from 5a (1.25 g,
4.21 mmol) after chromatography (cyclohexane/AcOEt, 7:3) by
using procedure G. M.p. 242 °C (ref.[40] 244 °C). 1H NMR
(400 MHz, CDCl3): δ = 1.50 (s, 18 H), 5.42 (s, 1 H), 7.45 (s, 2 H),
7.45 (d, J = 6 Hz, 2 H), 8.60 (d, J = 6 Hz, 2 H) ppm. 13C NMR
(100.6 MHz, CDCl3): δ = 30.4, 34.6, 121.5, 124.0, 129.4, 136.8,
149.3, 150.2, 155.1 ppm.
4-(3,5-Di-tert-butyl-4-hydroxyphenyl)-1,3-dimethylpyridinium Iodide
(18b): Compound 18b (1.29 g, 98 %) was obtained as colourless
crystals from biaryl 17b (891 mg, 3 mmol) by using procedure H.
1H NMR (400 MHz, CD3OD): δ = 1.49 (s, 18 H), 2.55 (s, 3 H),
4.36 (s, 3 H), 7.26 (s, 2 H), 7.90 (d, J = 6.5 Hz, 1 H), 8.65 (d, J =
6.5 Hz, 1 H), 8.77 (s, 1 H) ppm. 13C NMR (100.6 MHz, CD3OD):
δ = 18.6, 30.6, 35.8, 48.0, 127.1, 127.7, 128.6, 137.2, 139.8, 143.3,
146.9, 157.6, 160.1 ppm.
2,6-Di-tert-butyl-4-(3-methylpyridin-4-yl)phenol (17b): Compound
17b (1.53 g, 94 %) was obtained as colourless crystals from 5b
(1.7 g, 5.47 mmol) after chromatography (cyclohexane/AcOEt, 7:3)
by using procedure G. Sublimation was possible (150 °C, 1 Torr).
M.p. 208 °C. 1H NMR (400 MHz, CDCl3): δ = 1.48 (s, 18 H), 2.32
(s, 3 H), 5.41 (s, 1 H), 7.15 (s, 2 H), 7.17 (d, J = 5.0 Hz, 1 H), 8.44
(d, J = 5.0 Hz, 1 H), 8.47 (s, 1 H) ppm. 13C NMR (100.6 MHz,
CDCl3): δ = 17.6, 30.4, 34.6, 124.3, 125.6, 130.1, 130.7, 136.0,
4-(3,5-Di-tert-butyl-4-hydroxyphenyl)-1,3,5-trimethylpyridinium
Iodide (18c): Compound 18c (1.32 g, 97%) was obtained as colour-
less crystals from biaryl 17b (933 mg, 3 mmol) by using procedure
H. 1H NMR (400 MHz, CD3OD): δ = 1.46 (s, 18 H), 2.26 (s, 6 H),
4.33 (s, 3 H), 7.02 (s, 2 H), 8.64 (s, 2 H) ppm. 13 C NMR
(100.6 MHz, CD3OD): δ = 18.3, 30.7, 35.8, 48.0, 125.2, 126.7,
138.7, 140.3, 143.9, 156.3, 161.0 ppm.
147.4, 150.1, 151.4, 153.9 ppm. IR (KBr): ν = 633, 842, 887, 1021,
˜
4-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3,5-diethyl-1-methylpyridin-
ium Iodide (18d): Compound 18d (231 mg, 96%) was obtained as
colourless crystals from biaryl 17b (170 mg, 0.5 mmol) by using
procedure H. 1H NMR (400 MHz, CD3OD): δ = 1.15 (t, J =
7.6 Hz, 6 H), 1.47 (s, 18 H), 2.59 (q, J = 6.5 Hz, 4 H), 4.40 (s, 3 H),
7.01 (s, 2 H), 8.70 (s, 2 H) ppm. 13C NMR (100.6 MHz, CD3OD): δ
= 15.0, 25.6, 30.7, 35.8, 125.3, 126.3, 140.2, 143.4, 144.6, 156.1,
160.3 ppm.
1060, 1103, 1193, 1233, 1257, 1261, 1281, 1402, 1434, 1597, 2871,
2913, 2960, 2995, 3242 cm–1. C20H27NO (297.44): calcd. C 80.76,
H 9.15, N 4.71; found C 80.86, H 9.17, N 4.56.
2,6-Di-tert-butyl-4-(3,5-dimethylpyridin-4-yl)phenol (17c): Com-
pound 17c (8.15 g, 96%) was obtained as colourless crystals from
5c (1.7 g, 5.23 mmol) after chromatography (cyclohexane/AcOEt,
7:3) by using procedure G. M.p. 225 °C. 1H NMR (400 MHz,
CDCl3): δ = 1.45 (s, 18 H), 2.06 (s, 6 H), 5.26 (s, 1 H), 6.88 (s; 2
H), 8.32 (s, 2 H) ppm. 13C NMR (100.6 MHz, CDCl3): δ = 17.8,
30.6, 34.6, 124.9, 129.0, 131.4, 136.1, 148.5, 150.4, 153.1 ppm. IR
4-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3,5-diisopropyl-1-methyl-
pyridinium Iodide (18e): Compound 18e (296 mg, 97 %) was ob-
tained as colourless crystals from biaryl 17e (230 mg, 0.6 mmol) by
1
(KBr): ν = 880, 1070, 1105, 1130, 1236, 1249, 1283, 1423, 1432,
˜
using procedure H. H NMR (400 MHz, CD3OD): δ = 1.22 (d, J
1443, 1592, 1737, 2918, 2953, 3320 cm–1. HRMS (ESI-Q-Tof):
calcd. for C21H29NO [M]·+ 312.2322; found 312.2316.
= 6.8 Hz, 12 H), 1.45 (s, 18 H), 2.89 (hept, J = 6.8 Hz, 2 H), 4.42
(s, 3 H), 6.98 (s, 2 H), 8.74 (s, 2 H) ppm. 13C NMR (100.6 MHz,
CD3OD): δ = 23.4, 30.7, 30.9, 35.8, 49.0, 125.3, 126.3, 140.3, 142.1,
149.3, 156.2, 158.9 ppm.
2,6-Di-tert-butyl-4-(3,5-diethylpyridin-4-yl)phenol (17d): Compound
17d (610 mg, 89 %) was obtained as colourless crystals from 5d
(714 mg, 2.02 mmol) after chromatography (cyclohexane/AcOEt,
7:3) by using procedure G. M.p. 185 °C. 1H NMR (400 MHz,
CDCl3): δ = 1.04 (t, J = 7.6 Hz, 6 H), 1.44 (s, 18 H), 2.36 (q, J
= Hz 7.6 H, 4 H), 5.30 (s, 1 H), 6.89 (s, 2 H), 8.34 (s, 2 H) ppm.
13C NMR (100.6 MHz, CDCl3): δ = 15.8, 24.4, 30.6, 34.5, 125.1,
2,4-Di-tert-butyl-4-(1-methylpyridinium-4-yl)phenolate (2a): Com-
pound 2a (247 mg, 83%) was obtained as red crystals from 18a
(283 mg, 1 mmol) by using procedure I. M.p. 240–260 °C (dec.). 1H
NMR (400 MHz, CD3OD, [KOH] = 10–1 , [2a] = 10–2 ): δ = 1.41
(s, 18 H), 3.88 (s, 3 H), 7.57 (s, 2 H), 7.57 (d, J = 7.6 Hz, 2 H),
7.85 (d, J = 7.6 Hz, 2 H) ppm. 13C NMR (100.6 MHz, CD3OD,
[KOH] = 10–1 , [2a] = 10–2 ): δ = 30.6, 36.2, 44.9, 111.7, 117.5,
128.4, 135.8, 137.5, 147.5, 149.6, 153.1 ppm. IR (KBr): ν = 645,
˜
665, 684, 749, 780, 788, 873, 890, 1021, 1060, 1110, 1130, 1174,
1198, 1237, 1257, 1283, 1358, 1366, 1373, 1388, 1399, 1430, 1452,
126.0, 142.2, 142.3, 154.6, 180.8 ppm. IR (KBr): ν = 882, 1056,
˜
1573, 1591, 1600, 2873, 2915, 2936, 2962, 2997, 3290 cm–1
.
1100, 1161, 1192, 1198, 1256, 1307, 1315, 1320, 1348, 1393, 1444,
1457, 1476, 1481, 1499, 1498, 1539, 1578, 1581, 1585, 1649,
2948 cm–1. HRMS (ESI-Q-Tof): calcd. for C20H27NO [M]·+
298.2165; found 298.2175.
C23H33NO (339.53): calcd. C 81.37, H 9.80, N 4.13; found C 81.53,
H 9.86, N 4.23.
2,6-Di-tert-butyl-4-(3,5-diisopropylpyridin-4-yl)phenol (17e): Com-
pound 17e (1.25 g, 97%) was obtained as colourless crystals from
5e (1.3 g, 3.5 mmol) after chromatography (cyclohexane/AcOEt,
2,4-Di-tert-butyl-4-(1,3-dimethylpyridinium-4-yl)phenolate (2b):
Compound 2b (777 mg, 85%) was obtained as brown crystals from
1774
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Eur. J. Org. Chem. 2008, 1767–1776