A R T I C L E S
Li and Jones
All NMR spectra were recorded on a Bruker AMX400 spectrometer,
an AVANCE400 spectrometer, or an AVANCE500 spectrometer. GC-
MS was conducted on a Shimadzu QP-2010 spectrometer.
1.34 (t, 3H, J ) 7.6 Hz). 13C NMR: δ 163.84, 160.30, 155.49, 148.64,
130.65, 126.05, 115.36, 99.20, 97.27, 55.67, 55.54, 29.54, 18.97, 13.00.
MS: m/e 231, 230(bp), 215, 188, 172, 158, 145, 130, 115, 102, 89,
77. White solid.
2-Ethyl-3,5,8-trimethylquinoline (entry 6, Table 1). 1H NMR: δ
8.00 (s, 1H), 7.39 (d, 1H, J ) 6.8 Hz), 7.21 (d, 1H, J ) 6.8 Hz), 3.04
(q, 2H, J ) 7.2 Hz), 2.82 (s, 3H), 2.66 (s, 3H), 2.55 (s, 3H), 1.43 (t,
3H, J ) 7.6 Hz). 13C NMR: δ 160.71, 145.72, 134.57, 131.99, 130.99,
128.43, 127.73, 126.27, 125.61, 29.08, 19.22, 18.42, 17.77, 12.08. White
solid.
2-Ethyl-3,8-dimethylquinoline (entry 7, Table 1). 1H NMR: δ 7.78
(s, 1H), 7.53 (d, 1H, J ) 8.4 Hz), 7.44 (d, 1H, J ) 7.2 Hz), 7.32 (dd,
1H, J ) 7.6, 7.2 Hz), 2.98 (q, 2H, J ) 7.4 Hz), 2.80 (s, 3H), 2.46 (s,
3H), 1.42 (t, 3H, J ) 7.4 Hz). 13C NMR: δ 161.41, 145.54, 136.63,
135.39, 129.03, 128.16, 127.04, 125.16, 124.55, 29.17, 18.93, 17.75,
12.05. Oily liquid.
2-Ethyl-3,6-dimethylquinoline (entry 8, Table 1). 1H NMR: δ 7.91
(d, 1H, J ) 8.4 Hz), 7.74 (s, 1H), 7.45 (d, 1H, J ) 1.6 Hz), 7.42 (dd,
1H, J ) 8.8, 1.6 Hz), 2.97 (q, 2H, J ) 7.6 Hz), 2.50 (s, 3H), 2.47 (s,
3H), 1.36 (t, 3H, J ) 7.6 Hz). 13C NMR: δ 162.20, 145.21, 135.13,
135.07, 130.42, 129.22, 128.18, 127.28, 125.53, 29.36, 21.44, 19.04,
12.82. Oily liquid.
2-Ethyl-3-methyl-6-methoxyquinoline (entry 9, Table 1). 1H
NMR: δ 7.97 (d, 1H, J ) 8.8 Hz), 7.73 (s, 1H), 7.27 (dd, 1H, J ) 8.8,
2.8 Hz), 6.97 (d, 1H, J ) 2.8 Hz), 3.90 (s, 3H), 2.95 (q, 2H, J ) 7.6
Hz), 2.46 (s, 3H), 1.35 (t, 3H, J ) 7.6 Hz). 13C NMR: δ 160.62, 157.09,
142.63, 134.72, 129.90, 129.58, 128.08, 120.58, 104.46, 55.36, 29.17,
19.03, 12.85. White solid.
2-Ethyl-3,8-dimethyl-6-methoxyquinoline (entry 10, Table 1). 1H
NMR: δ 7.67 (s, 1H), 7.12 (d, 1H, J ) 1.6 Hz), 6.82 (d, 1H, J ) 2.8
Hz), 3.88 (s, 3H), 2.94 (q, 2H, J ) 7.6 Hz), 2.43 (s, 3H), 1.40 (t, 3H,
J ) 7.6 Hz). 13C NMR: δ 158.83, 156.63, 141.82, 138.43, 134.52,
129.36, 127.94, 120.36, 102.28, 55.20, 28.88, 18.92, 17.71, 12.13.
MS: m/e 215, 214(bp), 200, 187, 171, 157, 144, 128, 115, 91, 77.
White solid.
2-Ethyl-3-methyl-6-trifluoromethylquinoline (entry 11, Table 1).
1H NMR: δ 8.10 (d, 1H, J ) 8.8 Hz), 8.01 (s, 1H), 7.90 (s, 1H), 7.78
(dd, 1H, J ) 8.8, 2.0 Hz), 3.01 (q, 2H, J ) 7.2 Hz), 2.51 (s, 3H), 1.38
(t, 3H, J ) 7.6 Hz). 13C NMR: δ 165.69, 147.56, 136.14, 130.95,
129.62, 127.24, 126.18, 125.53, 124.60, 123.91, 29.51, 19.08, 12.44.
MS: m/e 239, 238(bp), 211, 190, 167, 140, 115, 87, 63. Light yellow
solid.
Procedure for the Reaction of N-Allylmethylamine. In a 50-mL
ampule equipped with a Teflon seal, 71.1 mg of N-methylallyl-
amine (1.00 mmol) and 24.3 mg of Co2(CO)8 (0.0711 mmol) were
added to 5 mL of dry THF in a glove box. Any dissolved nitrogen
was removed by freeze-pump-thaw degassing three times on a
Schlenk line. Carbon monoxide was then introduced at 1 atm, and the
reaction mixture was heated at 120 °C in an oil bath for 5 days with
stirring. The catalyst was removed by passing the reaction solution
through an alumina column followed by column chromatography to
isolate the product (silica gel, J.T. Baker, 40-140 mesh, 25% ethyl
acetate/hexane as eluent). The isolated yield of light yellow oily
1
1-methylpyrrolidin-2-one was 72.0 mg (0.73 mmol, 73%). H NMR:
δ 3.35 (t, 2H, J ) 7.2 Hz), 2.81 (s, 3H), 2.34 (t, 2H, J ) 8.0 Hz), 1.99
(tt, 2H, J ) 8.0, 7.2 Hz). 13C NMR: δ 175.03, 49.40, 30.66, 29.55,
17.64.
General Procedure for the Synthesis of Diallylaniline from
Aniline. In a 50-mL round-bottom flask fitted with a reflux condenser
and stir bar, 0.91 mL of aniline (9.8 mmol), 1.99 mL of allyl bromide
(0.023 mol), and 1.06 g Na2CO3 (0.01 mol) were added to 32 mL of
ethanol and 8 mL of H2O and refluxed overnight. The crude product
was extracted with diethyl ether and concentrated, dried over anhydrous
MgSO4, and distilled over potassium hydroxide to provide colorless
diallylaniline (1.60 g, 9.3 mmol, 93%).
General Procedure for the Conversion of Diallylanilines to
Quinolines. In a 50-mL ampule equipped with a Teflon seal, 173 mg
of diallylaniline (1.00 mmol) and 24.3 mg of Co2(CO)8 (0.0711 mmol)
were added to 5 mL of dry THF in a glove box. Any dissolved nitrogen
was removed by freeze-pump-thaw degassing three times on a
Schlenk line. Carbon monoxide was then introduced at 1 atm, and the
reaction mixture was heated at 105 °C in an oil bath for 48 h with
stirring (Caution: the pressure exceeds 1 atm and should be kept behind
a shield!). The catalyst was removed by passing the reaction solution
through an alumina column, and the product isolated by column
chromatography (silica gel, J.T. Baker, 40-140 mesh, 10% ethyl
acetate/hexane as eluent). The isolated yield of light yellow oily 2-ethyl-
3-methylquinoline was 111.3 mg (0.65 mmol, 65%). The following
quinolines were prepared using this methodology. Isolated yields of
quinolines are listed in Table 1.
1
2-Ethyl-3-methylquinoline (entry 1, Table 1). H NMR: δ 8.02
(d, 1H, J ) 8.4 Hz), 7.84 (s, 1H), 7.70 (d, 1H, J ) 8.0 Hz), 7.61 (dd,
1H, J ) 8.0, 7.2 Hz), 7.44 (dd, 1H, J ) 7.6, 7.2 Hz), 3.01 (q, 2H, J )
7.6 Hz), 2.49 (s, 3H), 1.37 (t, 3H, J ) 7.6 Hz). 13C NMR: δ 163.29,
146.67, 135.73, 129.40, 128.52, 128.28, 127.33, 126.69, 125.59, 29.49,
19.09, 12.85. Oily liquid.
2-Ethyl-3,6,8-trimethylquniloline (entry 2, Table 1). 1H NMR: δ
7.68 (s, 1H), 7.28 (s, 1H), 7.26 (s, 1H), 2.97 (q, 2H, J ) 7.6 Hz), 2.77
(s, 3H), 2.46 (s, 3H), 2.44 (s, 3H), 1.41 (t, 3H, J ) 7.6 Hz). 13C NMR:
δ 160.46, 144.14, 137.79, 136.19, 134.82, 130.45, 128.95, 127.12,
123.42, 29.06, 21.45, 18.94, 17.61, 12.10. White solid.
2-Ethyl-3,7,8-trimethylquinoline (entry 3, Table 1). 1H NMR: δ
7.73 (s, 1H), 7.45 (d, 1H, J ) 7.6 Hz), 7.25 (d, 1H, J ) 7.2 Hz), 2.97
(q, 2H, J ) 7.6 Hz), 2.77 (s, 3H), 2.48 (s, 3H), 2.44 (s, 3H), 1.44 (t,
3H, J ) 7.2 Hz). 13C NMR: δ 161.16, 145.48, 135.54, 135.32, 133.86,
128.22, 127.88, 125.37, 123.49, 29.17, 20.49, 18.79, 13.04, 12.02. White
solid.
Preparation of Diallylaniline-d5 from Deuteroaniline. In a 25-
mL ampule fitted with a reflux condenser and stir bar, 100 µL of
deuteroaniline (1.1 mmol), 238 µL of allyl bromide (2.5 mmol), and
116 mg of Na2CO3 (1.1 mmol) were added to 8 mL of EtOD and 2
mL of D2O and refluxed overnight. The crude product was extracted
with diethyl ether and concentrated, dried over anhydrous MgSO4, and
distilled to provide colorless diallylaniline-d5 (172 mg, 0.967 mmol,
87.9%).
Preparation of Diallylaniline-d15 from Deuteroaniline. The pro-
cedure was the same as for preparation of diallylaniline-d5 except that
238 µL of allyl bromide-d5 was used and refluxed for 60 h to provide
colorless diallylaniline-d15 (166 mg, 0.883 mmol, 80.3%). GCMS
analysis showed the product to contain 8% d14-diallylaniline, 11% d13-
diallylaniline, and 8% monoallylaniline-d10.
Procedure for the Conversion of Diallylaniline-d5, Diallylaniline-
d15 to Quinolines. In a 25-mL ampule equipped with a Teflon seal,
17.8 mg of diallylaniline-d5 (0.1 mmol) or 18.8 mg of diallylaniline-
d15 (0.1 mmol) and 8.5 mg of Co2(CO)8 (0.025 mmol) were added to
5 mL of dry THF in a glove box. Any dissolved nitrogen was removed
by freeze-pump-thaw degassing three times on a Schlenk line. Carbon
monoxide was then introduced at 1 atm, and the reaction mixture was
heated at 105 °C in an oil bath for 55 h with stirring. The catalyst was
removed by passing the reaction solution through an alumina column,
and THF was removed under vacuum followed by NMR analyses
2-Ethyl-3,5,7-trimethylquinoline (entry 4, Table 1). 1H NMR: δ
7.93 (s, 1H), 7.68 (s, 1H), 7.12 (s, 1H), 2.98 (q, 2H, J ) 7.6 Hz), 2.61
(s, 3H), 2.49 (s, 3H), 2.48 (s, 3H), 1.37 (t, 3H, J ) 7.6 Hz). 13C NMR:
δ 162.54, 147.16, 137.80, 133.05, 132.12, 128.33, 127.86, 125.88,
124.51, 29.36, 21.66, 19.27, 18.43, 12.84. White solid.
1
2-Ethyl-5,7-dimethoxy-3-methylquinoline (entry 5, Table 1). H
NMR: δ 8.11 (s, 1H), 6.96 (d, 1H, J ) 1.8 Hz), 6.44 (d, 1H, J ) 1.9
Hz), 3.94 (s, 3H), 3.92 (S, 3H), 2.94 (q, 2H, J ) 7.6 Hz), 2.44 (s, 3H),
9
10712 J. AM. CHEM. SOC. VOL. 129, NO. 35, 2007