(m), 1030 (m), 909 (w), 877 (w), 850 (w), 802 (w), 745 (m),
722 (m), 698 (s), 627 (w) and 530 (w).
(100 mL). Yield = 130 mg (22%). 1H NMR (CDCl3, 400 MHz):
8.19 (2H, d, J 7.8 Hz, ArH), 7.85 (1H, t, J 7.8 Hz, ArH), 4.55
(2H, d of t, J 9.3, 6.3 Hz, CH), 3.39 (2H, d of d, J 9.2, 1.9 Hz,
SCH) 3.12, (2H, d of d, J 9.2, 1.9 Hz, SCH), 2.14 (2H, sept., J
6.8 Hz, CH(CH3)2), 1.13 (6H, d, J 6.8 Hz, CH(CH3)2) and 1.05
(6H, d, J 6.8 Hz, CH(CH3)2). 13C NMR (CDCl3, 101 MHz):
150.5, 137.0, 123.0, 84.6, 34.1, 33.4, 19.7 and 19.9. IR (KBr,
cm−1): 3427 (m), 3134 (m), 2958 (m), 2867 (w), 1602 (s), 1566
(w), 1455 (m), 1401 (s), 1365 (w), 1308 (m), 1266 (w), 1228
(w), 1179 (w), 1024 (m), 993 (w), 957 (m), 941 (s), 886 (w),
824 (m), 741 (m), 647 (m), 589 (w) and 572 (w). MS (ESI): m/z
689, 356 (M + Na) and 334 (M + H). Elem. Anal. Calcd for
C17H23N3S2: C, 61.22; H, 6.95; N, 12.60. Found: C, 61.14; H,
7.01; N, 12.55.
MS (ESI): m/z 483 ([M + H]+, 100%). Elem. Anal. Calcd for
C24H23BrN2O4: C, 59.64; H, 4.80; N, 5.80. Found: C, 59.71; H,
4.71; N, 5.69.
2,6-Bis[(4R)-4-phenyl-4,5-dihydro-1,3-thiazol-2-yl]pyridine, L1
Triethylamine (6.2 g, 61.3 mmol) was added to a mixture of N,
N′-bis[(1R)-2-hydroxy-1-phenylethyl]pyridine-2,6-dicarboxa-
mide (0.50 g, 1.23 mmol) and phosphorus pentasulfide (0.83 g,
3.68 mmol) in dry toluene (80 mL). The mixture was heated to
reflux temperature and stirred for approximately 3 h. After the
mixture had cooled, water was added (20 mL) and the organic
layer separated and dried over sodium sulfate. Removal of the
solvent and recrystallisation from methanol gave a yellow solid.
2,6-Bis(4,4-diphenyl-4,5-dihydro-1,3-thiazol-2-yl]pyridine, L4
1
Yield = 0.15 g (30.4%). H NMR (CDCl3, 400 MHz): 8.34 (2H,
d, J 7.8 Hz, ArH), 7.91 (1H, t, J 7.8 Hz, ArH), 7.46–7.33 (10H,
m, ArH), 5.86 (2H, t, J 9.3 Hz, NCH), 3.85 (2H, d of d, J 11.2,
Prepared according to the procedure for L1 using N,N′-bis
(2-hydroxy-1,1-diphenylethyl)pyridine-2,6-carboxamide (2.00
g, 3.59 mmol), phosphorus pentasulfide (2.42 g, 10.89) and tri-
ethylamine (18.20 g, 179.86 mmol) in dry toluene (150 mL).
9.3 Hz, SCH2) and 3.36 (2H, d of d, J 11.2, 9.3 Hz, SCH2). 13
C
NMR (CDCl3, 101 MHz): 150.3, 141.6, 137.4, 128.9, 127.9,
126.7, 123.8, 81.0, 39.7 and 1.03. IR (KBr, cm−1): 3433 (m),
3134 (m), 2930 (w), 2907 (w), 1599 (s), 1582 (m), 1565 (w),
1491 (m), 1447 (s), 1429 (m), 1401 (m), 1313 (m), 1259 (w),
1212 (w), 1180 (w), 1155 (w), 1117 (w), 1079 (w), 1018 (s),
994 (m), 961 (w), 940 (s), 930 (m), 900 (w), 824 (m), 750 (s),
737 (m), 697 (s), 675 (w), 641 (m), 633 (m), 582 (w), 565 (w),
524 (w) and 424 (w). MS (ESI): m/z 825 (45%), 424 (M + Na,
35%) and 402 (M + H, 100%). Elem. Anal. Calcd for
C23H19N3S2: C, 68.80; H, 4.77; N, 10.46. Found: C, 68.73; H,
4.82; N, 10.40.
1
Yield = 1.06 g (53%). H NMR (CDCl3, 400 MHz): 8.41 (2H,
3
3
d, JHH = 7.8 Hz, ArH), 7.91 (1H, t, JHH = 7.8 Hz, ArH),
7.65–7.45 (8H, m, ArH), 7.44–7.21 (12H, m, ArH) and 4.04
(4H, s, ArH). 13C NMR (CDCl3, 101 MHz): 168.2, 150.7,
145.9, 137.3, 128.3, 127.2, 126.5, 123.5, 89.9 and 43.8. IR
(KBr, cm−1): 3392 (w), 3056 (w), 3025 (w), 2930 (w), 1683
(m), 1600 (m), 1495 (m), 1447 (s), 1316 (w), 1240 (w), 1156
(w), 1043 (m), 1029 (m), 1000 (w), 977 (w), 955 (w), 939 (m),
821 (w), 755 (m), 698 (s), 667 (w), 646 (w), 632 (w) and 609
(w). MS (ESI): m/z 554 ([M + H]+, 100%).
2,6-Bis[(4S)-4-tert-butyl-4,5-dihydro-1,3-thiazol-2-yl]pyridine, L2
2,6-Bis[4-(4-methylphenyl)-1,3-thiazol-2-yl]pyridine, L5
Prepared according to the procedure for L1 using triethylamine
(19.4 g, 191.7 mmol), N,N′-bis[(1S)-1-(hydroxymethyl)-2-tert-
butyl]pyridine-2,6-dicarboxamide (1.4, 3.83 mmol) and phos-
phorus pentasulfide (2.59 g, 11.5 mmol) in dry toluene
Pyridine-2,6-dithioamide (0.42 g, 2.13 mmol) and 2-bromo-4′-
methylacetophenone (0.95 g, 4.47 mmol) were heated at reflux
temperature in ethanol (40 mL) for 6 h. Upon cooling, water was
added and the white precipitate collected via filtration and dried
in vacuo. Yield = (0.586 mg, 65%). 1H NMR (CDCl3,
400 MHz): 8.39 (2H, d, J Hz, ArH), 7.98 (1H, t, J Hz, ArH),
7.93 (4H, d, J Hz, ArH), 7.16 (2H, s, CH), 7.29 (4H, d, J Hz,
ArH), and 2.43 (6H, s, CH3). 13C NMR (CDCl3, 101 MHz):
156.8, 151.0, 138.2, 131.6, 129.5, 126.3, 120.5, 115.0 and 21.4.
IR (KBr, cm−1): ν˜ 3427 (m), 3115 (m), 3022 (w), 2912 (w),
1583 (w), 1567 (s), 1530 (w), 1507 (m), 1463 (s), 1441 (m),
1403 (m), 1310 (w), 1292 (m), 1246 (w), 1216 (w), 1200 (w),
1183 (w), 1149 (m), 1122 (w), 1056 (m), 1041 (w), 1015 (w),
995 (s), 944 (w), 902 (w), 851 (w), 842 (w), 818 (s), 791 (m),
762 (s), 740 (m), 688 (w), 675 (m), 643 (m), 575 (w), 492 (m)
and 436 (w). MS (ESI): m/z 448 (100%, M + Na) and 426
(90%, M + H). Elem. Anal. Calcd for C25H19N3S2: C, 70.56; H,
4.50; N, 9.87. Found: C, 70.54; H, 4.40; N 9.75.
1
(150 mL). Yield = 0.62 g (45%). H NMR (CDCl3, 400 MHz):
8.19 (2H, d, J 7.7 Hz, ArH), 7.83 (1H, t, J 7.7 Hz, ArH), 4.47
(2H, d of d, J 9.5 Hz, SCH), 3.32 (2H, d of d, J 9.5 Hz, SCH)
and 3.20 (2H, t, J 10. 8Hz, CH) and 1.08 (18H, s, t-Bu). 13C
NMR (CDCl3, 101 MHz): 150.5, 137.0, 123.2, 88.2, 35.6, 32.7
and 26.8. IR (KBr, cm−1): 3438 (m), 3136 (m), 2952 (s), 2865
(m), 1612 (s), 1567 (m), 1521 (w), 1474 (m), 1456 (m), 1392
(m), 1359 (m), 1325 (m), 1314 (w), 1288 (m), 1192 (w), 1147
(w), 1056 (m), 998 (s), 976 (w), 941 (s), 922 (m), 817 (m), 784
(w), 733 (m), 649 (m), 613 (w) and 567 (w). MS (ESI): m/z 745,
384 (45%, M + Na) and 362 (100%, M + H). Elem. Anal. Calcd
for C19H27N3S2: C, 63.11; H, 7.53; N, 11.62. Found: C, 62.97;
H, 7.48; N, 11.63.
2,6-Bis[(4S)-4-iso-propyl-4,5-dihydro-1,3-thiazol-2-yl]pyridine, L3
6-Bis[4-tert-butyl-1,3-thiazol-2-yl]pyridine, L6
Prepared according to the procedure for L1, using triethylamine
(8.83 g, 87.3 mmol), N,N′-bis[(1S)-1-(hydroxymethyl)-2-methyl-
propyl]pyridine-2,6-dicarboxamide (589 mg, 1.75 mmol) and
phosphorus pentasulfide (1.18 g, 5.25 mmol) in dry toluene
Prepared according to the procedure for L5 using pyridine-2,6-
dithioamide (0.5 g, 2.53 mmol) and 1-bromopinacalone (1.23 g,
6.84 mmol) in ethanol (40 mL). Yield = (0.582 g, 64%). 1H
5958 | Dalton Trans., 2012, 41, 5949–5964
This journal is © The Royal Society of Chemistry 2012