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R. H. Prager et al.
methyl ether (ca. 100 mg) was heated in an evacuated sealed tube at
320◦C for 8 h and analyzed by means of 1H NMR spectroscopy and by
GC-MS.
4-pyrrolidinoquinolin-2(1H)-one, a white solid, mp 199–201◦, was col-
lected from the pyrolysis tube. (Found: M+ 214.1110. C13H14N2O
requires M+ 214.1106). δH 8.10–7.00 (4 H, m), 6.4 (1 H, s), 3.74 (4 H, t),
2.05 (4 H, t).
‘Crossover’ Reaction
2-Methoxy-4-pyrrolidinoquinoline
A solution of 1-methoxyisoquinoline (100 mg) and 2-ethoxypyridine
(100 mg) in chlorobenzene (600 µL) was dropped slowly, over 10 min,
into the vertical silica packed column, used above (0.01 mm, 700◦C).
The total contents of the trap and column washings were analyzed by
means of GC-MS.
A concentrated solution of sodium methoxide was prepared by dis-
solving solid sodium (1.0 g) in methanol (10 mL). To this was added
a solution of 2-chloro-4-pyrrolidinoquinoline (250 mg, 1.08 mmol) in
methanol (5 mL), and the mixture refluxed for 3 h. The solvent was
evaporated and the residue shaken with water (30 mL) and extracted
with ether (2 × 25 mL). The extract was dried and evaporated to give
the title compound (160 mg, 65%) as a pale yellow oil. (Found: M+
227.1202. C14H16N2O requires M+ 228.1263). δH 8.11 (1 H, dd, J 8.7,
1.5), 7.77 (1 H, dd, J 8.1, 1.5), 7.51 (1 H, dd, J 6.9, 1.5), 7.21 (1 H, dd,
J 6.9, 1.5), 6.00 (1 H, s), 4.03 (1 H, s), 3.62 (4 H, m), 2.01 (4 H, m). δC
164.6, 155.1, 148.5, 128.6, 127.8, 124.9, 121.4, 119.9, 91.9, 53.0, 52.0,
25.9, Mass spectrum m/z 227 (M+, 100%), 199 (29), 185 (10), 169 (7),
128 (15), 115 (17), 84 (40), 75 (9), 41 (12).
Pyrolysis of 2-Ethoxyquinoline
2-Ethoxyquinoline (100 mg, 5.78 mmol) was pyrolyzed under FVP con-
ditions (600◦C, 130◦C, 0.1 mm Hg). NMR spectrometry was used to
analyze the mixture of products obtained from the pyrolysis tube. The
major product (92%) was identified as quinolin-2-one. δH 8.30–7.30
(5 H, m), 6.30 (1 H, d, J 7.5). The second product (8%) was identified
as N-ethylquinolin-2-one. δH 7.80–7.10 (5 H, m), 6.72 (1 H, d, J 9),
4.37 (2 H, q, J 7), 1.38 (3 H, t, J 7.2). δC 166.7, 141.0, 139.0, 138.6,
130.6, 127.7, 122.7, 121.3, 37.3, 12.7.
Pyrolysis of 2-methoxy-4-pyrrolidinoquinoline
2-Methoxy-4-pyrrolidinoquinoline (100 mg, 0.44 mmol) was pyrolyzed
under FVP conditions (600◦C, 130◦C, 0.1 mm Hg). 1H NMR analysis
of the combined pyrolysate showed the presence of the starting material
(60%) and a single product (30%). N-Methyl-4-pyrrolidino-2-quinolone
was purified by column chromatography as a pale pink oil. (Found: M+
227.1240. C14H16N2O requires M+ 228.1263). δH 7.99 (1 H, dd, J 8.9,
1.5), 7.51 (1 H, dd, J 7.2, 1.5), 7.33 (1 H, dd, J 8.9, 1.7), 7.14 (1 H, dd,
J 7.2, 1.5), 5.86 (1 H, s), 3.65 (3 H, s), 3.59 (4 H, m), 1.99 (4 H, m).
δC 163.4, 155.2, 154.3, 129.9, 126.2, 120.2, 117.5, 114.6, 97.6, 52.1,
25.8, 25.7.
Reaction of 2,4-Dichloroquinoline with Pyrrolidine
Pyrrolidine (0.75 mL, 9.0 mmol) was added to a solution of 2,4-
dichloroquinoline (1.4 g, 7.07 mmol) in ethanol (5 mL), and the mixture
refluxed for 2 h. The solvent was evaporated and saturated sodium
carbonate (40 mL) added to the residue which was extracted with
dichloromethane (2 × 40 mL). The extract was dried and evaporated.
NMR analysis indicated the presence of equal quantities of the two
mono-substitution products. The product was purified by radial chro-
matography, eluting with ether/light petroleum (50 : 50). The first
fraction (10%) was unreacted starting material. The second fraction
(567 mg, 35%) was 4-chloro-2-pyrrolidinoquinoline, pale yellow crys-
tals, mp 76–79◦. (Found: M+ 232.0770. C13H13N2Cl requires M+
232.0767). δH 7.97 (1 H, dd, J 8.1, 1.5), 7.69 (1 H, d, J 8.9), 7.55
(1 H, dd, J 6.9, 1.5), 7.24 (1 H, dd, J 6.9, 1.5), 6.84 (1 H, s), 3.59 (4 H,
m), 2.04 (4 H, m). δC 155.0, 148.9, 142.7, 130.3, 126.4, 124.0, 121.9,
120.6, 109.9, 46.9, 25.4. The third fraction (326 mg, 20%) was 2-chloro-
4-pyrrolidinoquinoline, colourless needles, mp 99–101◦. (Found: M+
232.0768. C13H13N2Cl requires M+ 232.0767). δH 8.19 (1 H, d, J 8.7),
7.88 (1 H, dd, J 8.4, 1.5), 7.58 (1 H, dd, J 6.9, 1.5), 7.33 (1 H, dd, J 6.9,
1.5), 6.42 (1 H, s), 3.71 (4 H, m), 2.06 (4 H, m). δC154.0, 151.2, 149.3,
129.3, 128.7, 124.9, 123.3, 119.9, 101.7, 52.1, 25.8. Mass spectrum m/z
232 (M+, 100%), 203 (28), 189 (12), 162 (11), 140 (6), 128 (11), 101
(18), 75 (11), 43 (8).
Acknowledgments
The authors are grateful for support of this project by the
Australian Research Council.
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2-Ethoxy-4-pyrrolidinoquinoline
2-Chloro-4-pyrrolidinoquinoline (100 mg) was reacted with sodium
ethoxide as above at 80◦C for 16 h. The solvent was evaporated, and the
residue was extracted with ethyl acetate, and the extract washed with
water, dried and evaporated to give the title compound (100 mg, 95%),
which was used directly in the next experiment. (Found: M+ 242.1419.
C15H18N2O requires M+ 242.1419). δH 8.10–7.10 (4 H, m), 5.97 (1 H,
s), 4.45 (2 H, q, J 7.0), 3.59 (4 H, t, J 6.9), 2.02 (4 H, t, J 6.9), 1.42
(3 H, t, J 7.0). Mass spectrum m/z 242 (M, 73%), 227 (100), 214 (59),
198 (36), 185 (32), 171 (13), 145 (11), 116 (17), 84 (25), 70 (11), 51 (8).
Pyrolysis of 2-ethoxy-4-pyrrolidinoquinoline
2-Ethoxy-4-pyrrolidinoquinoline (100 mg, 0.41 mmol) was pyrolyzed
under FVP conditions (750◦C, 130◦C, 0.1 mm Hg) and the only product,