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dry THF at 0 ꢁC under N2. Aer being stirred for one hour, J ¼ 7.6 Hz, 2H), 6.94–6.86 (m, 3H), 6.73 (t, J ¼ 7.6 Hz, 1H), 3.04
methyl iodide (37.0 mL, 0.561 mol) was slowly added by a (s, 2H), 2.00 (s, 6H), 1.92 (s, 6H), 1.52 (s, 6H), 1.41 (s, 3H). 13C
syringe; then the mixture was stirred at ambient temperature NMR (CDCl3,100 MHz, TMS): d 175.0, 167.8, 156.3, 151.5, 149.7,
for ten hours. The reaction mixture was cooled to 0 ꢁC, 148.8, 143.6, 134.7, 127.9, 127.4, 125.5, 125.0, 123.0, 122.6,
quenched with water slowly, and extracted with ethyl acetate. 122.0, 43.1, 42.5, 29.9, 28.0, 18.1, 18.0, 15.9.
The organic layer was washed with brine, water, dried over
2-(1-(2,6-Diethylphenylimino)ethyl)-7-(2,6-diethylphenyl imino)-
MgSO4, and ltered. The ltrate was evaporated in vacuo to 6,6-dimethyl cyclopentapyridine (L2). Using the same proce-
afford a crude product, which was puried by column dure as for the synthesis of L1, L2 was obtained as yellow oil
chromatography on silica gel to give 2-chloro-6,6- (0.25 g, 49.9%). FT-IR (KBr, cmꢀ1): 2962.1, 2927.8, 2867.7,
dimethylcyclopentapyridin-7-one of 11.6 g as white solid. FT- 1666.5, 1644.7, 1454.2, 1365.5, 1261.1, 1161.6, 1110.1, 1041.6,
IR (KBr, cmꢀ1): 3082.5, 3047.0, 2972.8, 2932.2, 2866.7, 1719.8, 844.5, 772.6, 737.2, 701.9. Anal. Calcd for C32H39N3: C, 82.53; H,
1578.9, 1465.6, 1430.4, 1375.6, 1310.5, 1176.3, 1126.0, 1085.1, 8.44; N, 9.02. Found: C, 82.24; H, 8.63; N, 9.15. 1H NMR (CDCl3,
1025.2, 1000.5, 915.1, 872.5, 846.7, 820.4, 730.2, 657.4. Anal. 400 MHz, TMS): d 8.25 (d, J ¼ 8.0 Hz, 1H), 7.76 (d, J ¼ 8.0 Hz,
Calcd for C10H10ClNO: C, 61.39; H, 5.15; N, 7.16. Found: C, 1H), 7.06 (d, J ¼ 7.2 Hz, 2H), 7.00–6.97 (m, 3H), 6.84 (t, J ¼ 7.6
61.02; H, 5.29; N, 6.82. 1H NMR (CDCl3, 500 MHz, TMS): d 7.81 Hz, 1H), 3.06 (s, 2H), 2.50–2.41 (m, 2H), 2.38–2.18 (m, 6H), 1.54
(d, J ¼ 8.5 Hz, 1H), 7.51 (d, J ¼ 8.0 Hz, 1H), 2.98 (s, 2H), 1.30 (s, (s, 6H), 1.42 (s, 3H), 1.09–1.05 (m, 12H). 13C NMR (CDCl3,100
6H). 13C NMR (CDCl3, 125 MHz, TMS): d 201.3, 154.7, 143.6, MHz, TMS): d 174.7, 167.7, 156.2, 151.4, 148.8, 147.8, 143.5,
140.5, 135.1, 126.7, 42.6, 41.2, 25.3.
134.6, 131.2, 130.6, 125.9, 125.5, 123.2, 122.3, 122.2, 42.9, 42.3,
Synthesis of 2-acetyl-6,6-dimethylcyclopentapyridin-7-one. 27.7, 24.7, 24.5, 16.2, 13.9, 13.7.
2-Chloro-6,6-dimethylcyclopentapyridin-7-one (9.50 g, 0.049
2-(1-(2,4,6-Trimethylphenylimino)ethyl)-7-(2,4,6-trimethyl-
mol), tributyl(1-ethoxyvinyl)tin (19.3 g, 0.053 mol), Pd(dppf)Cl2 phenylimino)-6,6-dimethylcyclopentapyridine (L3). Using the
(1.07 g, 1.47 mmol), and 100 mL of 1,4-dioxane were added to a same procedure as for the synthesis of L1, L3 was obtained as
250 mL three-necked jacketed ask. The mixture was reuxed yellow oil (0.23 g, 48.6%). FT-IR (KBr, cmꢀ1): 2917.3, 2857.3,
for 12 h under N2, and cooled to room temperature. Then the 1666.9, 1642.6, 1474.7, 1455.8, 1365.9, 1267.0, 1214.1, 1165.2,
mixture was washed with KF solution (0.3 M, 50 mL ꢂ 3) and 1146.4, 1112.1, 1042.0, 1011.3, 849.7, 743.2, 706.0. Anal. Calcd
treated with aqueous HCl (1.2 M, 100 mL). The resulting for C30H35N3: C, 82.34; H, 8.06; N, 9.60. Found: C, 82.13; H, 8.25;
mixture was neutralized by NaOH solution and extracted with N, 9.30. 1H NMR (CDCl3, 400 MHz, TMS): d 8.28 (d, J ¼ 8.0 Hz,
CH2Cl2. The organic layer was dried over anhydrous Na2SO4 and 1H), 7.73 (d, J ¼ 8.0 Hz, 1H), 6.84 (s, 2H), 6.74 (s, 2H), 3.02 (s,
concentrated in vacuo to afford the crude product. The residue 2H), 2.27 (s, 3H), 2.15 (s, 3H), 1.95 (s, 6H), 1.89 (s, 6H), 1.95 (s,
was puried by silica gel chromatography to afford 8.1 g 6H), 1.51 (s, 6H), 1.43 (s, 3H). 13C NMR (CDCl3,100 MHz, TMS): d
2-acetyl-6,6-dimethylcyclopentapyridin-7-one of as pale yellow 175.2, 167.9, 156.1, 151.4, 147.0, 146.2, 143.3, 134.4, 132.1,
solid. FT-IR (KBr, cmꢀ1): 2968.8, 2870.3, 1724.3, 1692.4, 1580.2, 130.8, 128.4, 127.9, 125.2, 124.7, 122.4, 42.9, 42.3, 27.8, 20.7,
1458.8, 1424.3, 1383.6, 1362.7, 1296.6, 1272.3, 1158.5, 1106.7, 20.6, 17.9, 17.8, 15.4.
1025.0, 1004.3, 955.3, 905.7, 879.4, 854.5, 822.5, 743.7, 678.0.
2-(1-(2,6-Diethyl-4-methylphenylimino)ethyl)-7-(2,6-diethyl-
Anal. Calcd for C12H13NO2: C, 70.92; H, 6.45; N, 6.89. Found: C, 4-methylphenylimino)-6,6-dimethylcyclopentapyridine (L4).
70.58; H, 6.13; N, 6.72. 1H NMR (CDCl3, 500 MHz, TMS): d 8.24 Using the same procedure as for the synthesis of L1, L4 was
(d, J ¼ 8.0 Hz, 1H), 7.98 (d, J ¼ 8.0 Hz, 1H), 3.08 (s, 2H), 2.83 (s, obtained as yellow oil (0.22 g, 42.0%). FT-IR (KBr, cmꢀ1): 2962.3,
3H), 1.33 (s, 6H). 13C NMR (CDCl3, 125 MHz, TMS): d 201.7, 2927.5, 2866.6, 1665.5, 1644.1, 1458.1, 1365.8, 1263.0, 1211.9,
198.2, 153.4, 151.5, 138.1, 137.6, 123.2, 42.7, 41.5, 27.3, 25.2.
1165.3, 1112.1, 1041.6, 856.2, 805.5, 736.8, 702.0. Anal. Calcd for
C
34H43N3: C, 82.71; H, 8.78; N, 8.51. Found: C, 82.36; H, 8.64; N,
8.32. 1H NMR (CDCl3, 400 MHz, TMS): d 8.21 (d, J ¼ 8.0 Hz, 1H),
7.74 (d, J ¼ 8.0 Hz, 1H), 6.89 (s, 2H), 6.78 (s, 2H), 3.03 (s, 2H),
2.44–2.35 (m, 4H), 2.32 (s, 3H), 2.31–2.17 (m, 4H), 2.15 (s, 3H),
Synthesis and characterization of organic compounds (L1–L5)
2-(1-(2,6-Dimethylphenylimino)ethyl)-7-(2,6-dimethylphenyl-
imino)-6,6-dimethylcyclopentapyridine (L1). 2,6-Dimethylani- 1.52 (s, 6H), 1.43 (s, 3H), 1.07 (t, J ¼ 6.4 Hz, 6H), 1.05 (t, J ¼ 6.4
line (0.31 g, 2.5 mmol) was added to a solution of 2-acetyl-6,6- Hz, 6H). 13C NMR (CDCl3, 100 MHz, TMS): d 175.0, 167.9, 156.1,
dimethylcyclopentapyridin-7-one (0.20 g, 1.0 mmol) with a 151.4, 146.3, 145.2, 143.3, 134.5, 132.3, 131.1, 131.0, 130.5,
catalytic amount of p-toluenesulfonic acid (20.0 mg, 0.1 mmol) 126.7, 126.1, 122.2, 42.9, 42.3, 27.7, 24.6, 24.5, 21.0, 20.9, 15.9,
in 30 mL of n-butanol. The mixture was stirred for 8 h at 14.0, 13.8.
reuxing temperature. Under reduced pressure, the solvent was
2-(1-(2,6-Diisopropylphenylimino)ethyl)-7-(2,6-diisopropyl-
evaporated and the residue was subsequently puried by silica phenylimino)-6,6-dimethylcyclopentapyridine (L5). Using the
gel chromatography to afford 0.28 g (yield: 62.9%) of yellow oil. same procedure as for the synthesis of L1, L5 was obtained as
FT-IR (KBr, cmꢀ1): 2919.6, 2854.7, 1669.7, 1645.5, 1591.6, yellow oil (0.28 g, 50.3%). FT-IR (KBr, cmꢀ1): 2961.1, 2927.5,
1462.5, 1434.3, 1363.0, 1295.9, 1259.2, 1207.2, 1185.5, 1159.1, 2866.6, 1666.2, 1638.5, 1586.3, 1457.2, 1433.5, 1378.4, 1375.5,
1110.7, 1085.8, 1040.8, 918.8, 888.6, 845.5, 817.1, 748.1, 732.1, 1361.5, 1302.8, 1108.9, 1043.4, 843.1, 801.5, 773.3, 739.4. Anal.
685.4. Anal. Calcd for C28H31N3: C, 82.11; H, 7.63; N, 10.26. Calcd for C36H47N3: C, 82.87; H, 9.08; N, 8.05. Found: C, 82.49;
Found: C, 81.92; H, 7.94; N, 10.16. H NMR (CDCl3, 400 MHz, H, 9.32; N, 8.21. 1H NMR (CDCl3, 400 MHz, TMS): d 8.16 (d, J ¼
1
TMS): d 8.30 (d, J ¼ 8.0 Hz, 1H), 7.76 (d, J ¼ 8.0 Hz, 1H), 7.00 (d, 8.0 Hz, 1H), 7.76 (d, J ¼ 8.0 Hz, 1H), 7.10 (d, J ¼ 6.8 Hz, 2H), 7.04
32726 | RSC Adv., 2015, 5, 32720–32729
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