R. Surasani et al. / Journal of Fluorine Chemistry 135 (2012) 91–96
95
ammonium acetate (1 mmol), FeF3 (5 mol%) and ethanol (5 mL)
was placed in a 25 mL round bottomed flask equipped with a cold
water condenser and calcium chloride guard tube. The reaction
mixture was slowly heated to 75–80 8C. Typically the reaction
completed within one hour. After completion of the reaction (TLC),
the mixture was cooled and 15 mL of ethyl acetate and 5 mL of
water was added to the flask. The ethyl acetate layer was separated
and washed with cold water (20 mL). The organic layer was then
dried over anhydrous sodium sulfate, filtered and the solvent
distilled under vacuum to afford the crude product. The crude
product was finally recrystallized from ethanol to afford the pure
products 5a–5p. The aqueous layer containing the catalyst (FeF3)
was evaporated under reduced pressure to give a solid (slight pale
pink in color). The IR spectrum of the recovered catalyst was
identical to that of the commercially available catalyst (Aldrich),
which was further reused for the next reaction without loss in
activity. The catalyst has been recovered and reused five times
(reaction yields: 90, 89, 89, 88% and 87%).
730 cmÀ1. 1H NMR (400 MHz, DMSO-d6)
d
0.88 (s, 3H), 1.01 (s, 3H),
1.17 (t, J = 7.2 Hz, 3H), 2.00 (d, J = 16.4 Hz, 1H), 2.19 (d, J = 16.4 Hz,
1H), 2.30–2.26 (m, 4H), 2.44 (d, J = 17.2 Hz, 1H), 3.65 (s, 3H, OCH3),
3.66 (s, 3H, OCH3), 4.02 (q, J = 7.2 Hz, 2H), 4.79 (s, 1H), 6.63 (dd,
J = 2.0 & 8.4 Hz 1H), 6.77–6.74 (m, 2H), 9.02 (s, 1H, NH). 13C NMR
(50 MHz, DMSO-d6)
d 14.2, 18.2, 26.4, 29.2, 32.1, 35.1, 50.3, 55.3,
55.4, 59.0, 103.8, 110.0, 111.4, 111.7, 119.2, 140.4, 144.5, 146.9,
147.9, 149.3, 166.8, 194.2. MS (ES) m/z 400.50 (M+1). HRMS (ESI)
calculated for C23H30NO5 (M+H)+ 400.2124 found 400.2127.
Ethyl
2,7,7-trimethyl-5-oxo-4-(4-(trifluoromethyl)
phenyl)-
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (compound 5f). A yellow
solid; IR (KBr) 3281, 2938, 1710, 1603, 1496, 1382, 1324, 1216, 1136,
1065, 862, 598, 531 cmÀ1 1H NMR (400 MHz, DMSO-d6)
. d 0.83 (s,
3H), 1.00 (s, 3H), 1.13 (t, J = 7.2 Hz, 3H), 2.00 (d, J = 16.0 Hz, 1H), 2.19
(d, J = 16.4 Hz, 1H), 2.32 (m, 4H), 2.45 (d, J = 16.4 Hz, 1H), 3.99 (q,
J = 7.2 Hz, 2H), 4.93 (s, 1H), 7.37 (d, J = 8.0 Hz, 2H), 7.57 (d, J = 7.6 Hz,
2H), 9.17 (s, 1H, NH). 13C NMR (50 MHz, DMSO-d6)
d 14.1, 18.3, 26.5,
29.0, 32.1, 36.3, 50.1, 59.1, 102.8, 109.3, 124.6, 124.7, 128.2, 145.7,
149.8, 151.8, 166.6, 194.1. MS (ES) m/z 408.50 (M+1). HRMS (ESI)
calculated for C22H25NO3F3 (M+H)+ 408.1787 found 408.1786.
Ethyl 4-(3,4-dihydroxyphenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-
hexahydroquinoline-3-carboxylate (compound 5g). A brown solid; IR
(KBr) 3504, 3276, 2960, 1681, 1603, 1487, 1380, 1286, 1217, 1074,
Ethyl 2,7,7-trimethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,6,7,8-hexa-
hydroquinoline-3-carboxylate (compound 5a). A pale yellow solid;
IR (KBr) 3289, 2959, 1702, 1607, 1528, 1487, 1349, 1217, 1073,
683 cmÀ1. 1H NMR (400 MHz, DMSO-d6)
d 0.83 (s, 3H), 1.01 (s, 3H),
1.13 (t, J = 7.2 Hz, 3H), 2.00 (d, J = 16.4 Hz, 1H), 2.21 (d, J = 16.0 Hz,
1H), 2.38 (m, 4H), 2.48 (d, J = 17.2 Hz, 1H), 3.98 (q, J = 7.2 Hz, 2H),
814, 659 cmÀ1. 1H NMR (400 MHz, DMSO-d6)
d 0.87 (s, 3H), 1.00 (s,
4.96 (s, 1H), 7.62–7.50 (m, 2H), 7.98 (m, 2H), 9.24 (s, 1H, NH). 13
C
3H), 1.16 (t, J = 7.2 Hz, 3H), 1.99 (d, J = 16.0 Hz, 1H), 2.16 (d,
J = 16.0 Hz, 1H), 2.27 (m, 4H), 2.40 (d, J = 17.2 Hz, 1H), 4.00 (q,
J = 7.2 Hz, 2H), 4.68 (s, 1H), 6.39 (dd, J = 2.0 and 8.4 Hz, 1H), 6.51 (d,
J = 8.0 Hz, 1H), 6.57 (d, J = 2.0 Hz, 1H), 8.45 (s, 1H, OH), 8.56 (s, 1H,
NMR (50 MHz, DMSO-d6)
d 14.0, 18.3, 26.3, 29.0, 32.2, 36.4, 50.0,
59.2, 102.6, 109.2, 120.8, 121.9, 129.3, 134.2, 146.0, 147.3, 149.6,
150.3, 166.3, 194.2. MS (ES) m/z 385.10 (M+1). HRMS (ESI)
calculated for C21H25N2O5 (M+H)+ 385.1763 found 385.1769.
Ethyl 4-(4-chlorophenyl)-2,7,7-trimethyl-5-oxo-1,4,5, 6,7,8-hex-
ahydroquinoline-3-carboxylate (compound 5b). A off-white solid;
IR (KBr) 3275, 2958, 1706, 1604, 1488, 1381, 1214, 1214, 1071,
OH), 8.94 (s, 1H, NH). 13C NMR (100 MHz, DMSO-d6)
d 14.2, 18.0,
26.6, 29.2, 32.1, 34.9, 50.4, 59.0, 104.1, 110.3, 114.8, 115.2, 118.1,
138.6, 143.1, 144.1, 144.6, 149.0, 167.1, 194.3. MS (ES) m/z 372.60
(M+1). HRMS (ESI) calculated for C21H26NO5 (M+H)+ 372.1811
found 372.1817.
844, 534 cmÀ1. 1H NMR (400 MHz, DMSO-d6)
d0.83 (s, 3H), 1.00 (s,
3H), 1.13 (t, J = 7.2 Hz, 3H), 1.99 (d, J = 16.0 Hz, 1H), 2.19 (d,
J = 16.0 Hz, 1H), 2.25–2.28 (m, 4H), 2.43 (d, J = 17.2 Hz, 1H), 3.99
(q, J = 7.2 Hz, 2H), 4.83 (s, 1H), 7.16 (d, J = 8.4 Hz, 2H), 7.25 (d,
Ethyl
1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (compound 5h).
yellow solid; IR (KBr) 3486, 3310, 2956, 1698, 1607, 1494, 1280,
1218, 1066, 856, 613 cmÀ1. 1H NMR (400 MHz, DMSO-d6)
0.79 (s,
4-(5-hydroxy-2-nitrophenyl)-2,7,7-trimethyl-5-oxo-
A
J = 8.0 Hz, 2H), 9.12 (s, 1H, NH). 13C NMR (50 MHz, DMSO-d6)
d
4.1,
d
18.3, 26.4, 29.0, 32.1, 35.6, 50.1, 59.0, 103.0, 109.6, 127.6, 129.2,
130.2, 145.3, 146.5, 149.5, 166.5, 194.1. MS (ES) m/z 374.00 (M+1).
HRMS (ESI) calculated for C21H25NO3Cl (M+H)+ 374.1763 found
374.1756
Ethyl 2,7,7-trimethyl-4-(4-nitrophenyl)-5-oxo-1,4,5, 6,7,8-hexa-
hydroquinoline-3-carboxylate (compound 5c). A yellow solid; IR
(KBr) 3295, 2959, 1699, 1605, 1517, 1482, 1345, 1218, 1073, 836,
694 cmÀ1. 1H NMR (400 MHz, DMSO-d6)
d 0.82 (s, 3H), 1.00 (s, 3H),
3H), 0.98 (s, 3H), 1.00 (t, J = 7.2 Hz, 3H), 1.92 (d, J = 15.6 Hz, 1H),
2.13 (d, J = 15.6 Hz, 1H), 2.25 (d, J = 16.8 Hz, 1H), 2.29 (s, 3H), 2.42
(d, J = 16.8 Hz, 1H), 3.94 (q, J = 7.2 Hz, 2H), 5.77 (s, 1H), 6.62 (dd,
J = 2.4 & 8.8 Hz, 1H), 6.75 (d, J = 2.4 Hz, 1H), 7.69 (d, J = 8.8 Hz, 1H),
9.06 (s, 1H, NH), 10.37 (s, 1H, OH). 13C NMR (100 MHz, DMSO-d6)
d
13.8, 18.2, 26.3, 28.8, 31.7, 32.0, 50.1, 59.0, 103.5, 100.3, 113.3,
166.5, 126.3, 140.1, 145.4, 145.8, 149.4, 161.5, 166.7, 193.9. MS
(ES) m/z 401.50 (M+1). HRMS (ESI) calculated for C21H25N2O6
(M+H)+ 401.1713 found 401.1721.
Ethyl 4-(4-methoxyphenyl)-2,7,7-trimethyl-5-oxo-1,4, 5,6,7,8-
hexahydroquinoline-3-carboxylate (compound 5i). A white solid;
IR (KBr) 3279, 2958, 1699, 1605, 1492, 1380, 1214, 1072, 1031,
849, 762, 536 cmÀ1 1H NMR (400 MHz, DMSO-d6)
. d 0.85 (s, 3H),
1.00 (s, 3H), 1.15 (t, J = 7.2 Hz, 3H), 1.98 (d, J = 16.0 Hz, 1H), 2.17 (d,
J = 16.0 Hz, 1H), 2.29 (m, 4H), 2.43 (d, J = 16.8 Hz, 1H), 3.67 (s, 3H,
OCH3), 3.99 (q, J = 7.2 Hz, 2H), 4.78 (s, 1H), 6.74 (d, J = 8.4 Hz, 2H),
7.05 (d, J = 8.4 Hz, 2H), 9.00 (s, 1H, NH). 13C NMR (100 MHz, DMSO-
1.12 (t, J = 7.2 Hz, 3H), 1.99 (d, J = 16.0 Hz, 1H), 2.20 (d, J = 16.0 Hz,
1H), 2.27–2.31 (m, 4H), 2.45 (d, J = 16.4 Hz, 1H), 3.98 (q, J = 7.2 Hz,
2H), 4.96 (s, 1H), 7.42 (d, J = 8.8 Hz, 2H), 8.10 (d, J = 8.8 Hz, 2H), 9.23
(s, 1H, NH). 13C NMR (50 MHz, DMSO-d6)
d 14.0, 18.3, 26.4, 29.0,
32.1, 36.6, 50.0, 59.2, 102.3, 109.0, 123.0, 128.7, 145.6, 146.0, 150.0,
154.9, 166.3, 194.1. MS (ES) m/z 385.10 (M+1). HRMS (ESI)
calculated for C21H25N2O5 (M + H)+ 385.1763 found 385.1756.
Ethyl 4-(4-cyanophenyl)-2,7,7-trimethyl-5-oxo-1,4,5, 6,7,8-hexa-
hydroquinoline-3-carboxylate (compound 5d). A ash solid; IR (KBr)
3296, 2959, 2226, 1697, 1606, 1488, 1379, 1219, 1074, 845,
d6)
d 14.2, 18.2, 26.5, 29.1, 32.1, 34.9, 50.3, 54.8, 59.0, 103.9, 110.1,
555 cmÀ1. 1H NMR (400 MHz, DMSO-d6)
d
0.81 (s, 3H), 1.00 (s, 3H),
113.1, 128.4, 140.0, 144.6, 149.2, 157.3, 166.9, 194.2, MS (ES) m/z
370.50 (M+1). HRMS (ESI) calculated for C22H28NO4 (M+H)+
370.2018 found 370.2025.
Ethyl 4-(2-chloro-3-(trifluoromethyl)phenyl)-2,7,7-trimethyl-5-
oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate (compound 5j). A
white solid; IR (KBr) 3297, 2961, 1701, 1614, 1492, 1380, 1312,
1216, 1133, 803, 735, 597 cmÀ1 1H NMR (400 MHz, DMSO-d6)
. d
1.12 (t, J = 7.2 Hz, 3H), 1.99 (d, J = 16.4 Hz, 1H), 2.19 (d, J = 16.4 Hz,
1H), 2.30–2.26 (m, 4H), 2.44 (d, J = 17.2 Hz, 1H), 3.98 (q, J = 7.2 Hz,
2H), 4.90 (s, 1H), 7.34 (d, J = 8.0 Hz, 2H), 7.68 (d, J = 8.0 Hz, 2H), 9.19
(s, 1H, NH). 13C NMR (50 MHz, DMSO-d6)
d 14.1, 18.3, 26.4, 29.0,
32.1, 36.7, 50.1, 59.1, 102.4, 108.5, 109.1, 119.0, 128.5, 131.8, 146.0,
149.9, 152.8, 166.3, 194.1. MS (ES) m/z 365.10 (M+1). HRMS (ESI)
calculated for C22H25N2O3 (M+H)+ 365.1865 found 365.1852.
Ethyl 4-(3,4-dimethoxyphenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-
hexahydroquinoline-3-carboxylate (compound 5e). A white solid; IR
(KBr) 3279, 2957, 1695, 1604, 1491, 1379, 1216, 1139, 1031, 788,
0.85 (s, 3H), 1.00 (s, 3H), 1.15 (t, J = 7.2 Hz, 3H), 1.98 (d, J = 16.0 Hz,
1H), 2.17 (d, J = 16.0 Hz, 1H), 2.29 (m, 4H), 2.43 (d, J = 16.8 Hz, 1H),
3.99 (q, J = 7.2 Hz, 2H), 5.31 (s, 1H), 7.40 (m, 1H), 7.59 (m, 2H), 9.17
(s, 1H, NH). 13C NMR (50 MHz, DMSO-d6)
d 13.9, 18.3, 26.4, 29.0,