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J. G. Rodrıguez et al. / Tetrahedron 61 (2005) 9042–9051
9048
3.50 (s, 1H, OH), 7.54 (ddd, 1H, J5–6Z8.1 Hz, J6–7
7.0 Hz, J6–8Z1.1 Hz, H-6), 7.70 (ddd, 1H, J7–8Z8.1 Hz,
J6–7Z7.0 Hz, J5–7Z1.6 Hz, H-7), 7.75 (dd, 1H, J5–6
8.1 Hz, J5–7Z1.6 Hz, H-5), 8.10 (dd, 1H, J7–8Z8.1 Hz,
J6–8Z1.1 Hz, H-8) and 8.20 (d, 1H, J2–4Z2.1 Hz, H-4) and
9.04 (d, 1H, J2–4Z2.1 Hz, H-2).
Z
J5–7Z1.6 Hz, H-7), 7.77 (dd, 1H, J5–6Z8.1 Hz, J5–7Z
1.6 Hz, H-5), 8.10 (dd, 1H, J7–8Z8.6 Hz, J6–8Z1.6 Hz,
H-8) and 8.12 (d, 1H, J3–4Z8.1 Hz, H-4); dC (50 MHz,
CDCl3) 77.5 (ArC^C–H), 83.3 (ArC^C–H), 124.0 (C-3),
127.3 (C-4a, C-5 and C-6), 129.2 (C-7), 130.0 (C-8), 136.1
(C-4), 142.3 (C-8a) and 147.9 (C-2); m/z 153 (MC, 100),
126 (30) and 76 (19); lmax(CH2Cl2)/nm 240, 285, 316
and 330.
Z
C14H13ON (211.26). Anal. Calcd C 79.59, H 6.20, N 6.63;
found: C 79.38, H 6.34, N 6.52.
C11H7N (153.18). Anal. Calcd C 86.25, H 4.61, N 9.14;
found: C 86.36, H 4.65, N 9.27.
4.1.9. 2-Methyl-4-(40-quinolyl)-but-3-yn-2-ol (9). Following
the preparation of 7, a mixture of 4-chloroquinoline (2)
(2.0 g, 12.22 mmol), 2-methylbut-3-yn-2-ol (1.33 mL,
13.45 mmol) in freshly distilled diethylamine (7 mL), was
added dichloro bis(triphenylphosphine) palladium (86 mg,
0.12 mmol, 0.9%) and cuprous iodide (4.7 mg, 0.02 mmol,
0.15%). The mixture was stirred for 2 days at the reflux
temperature, giving (9) (2.19 g, 86%) as a yellow solid, mp
100–102 8C. dH (200 MHz, CDCl3) 1.71 (s, 6H, 2!CH3),
3.54 (s, 1H, OH), 7.13 (d, 1H, J2–3Z4.7 Hz, H-3), 7.31
(ddd, 1H, J5–6Z8.6 Hz, J6–7Z7.0 Hz, J6–8Z1.1 Hz, H-6),
7.50 (ddd, 1H, J7–8Z8.6 Hz, J6–7Z7.0 Hz, J5–7Z1.6 Hz,
H-7), 8.00 (dd, 1H, J5–6Z8.6 Hz, J5–7Z1.6 Hz, H-5), 8.06
(dd, 1H, J7–8Z8.6 Hz, J6–8Z1.1 Hz, H-8) and 8.66 (d, 1H,
J2–3Z4.7 Hz, H-2). C14H13ON (211.26). Anal. Calcd C
79.59, H 6.20, N 6.63; found: C 79.63, H 6.10, N 6.33.
4.1.12. 3-Ethynylquinoline (12). Following the preparation
of 11, 2-methyl-4-(30-quinolyl)but-3-yn-2-ol (8) (4.5 g,
21.3 mmol) in dry toluene (15 mL) and powder of sodium
hydroxide (0.1 g, 2.5 mmol) at reflux temperature for 4 h,
gave an orange solid, which was purified by sublimation on
a cool-finger surface (40 Torr) at 50 8C. The 3-ethynylqui-
noline (12) was isolated as colourless crystals, 2.84 g, 87%,
mp 78–79 8C.9b nmax(KBr)/cmK1 3165 (^C–H st), 2095
(C^C st), 1620, 1600, 1560, and 1490 (C]C and C]N st
conj.), 790 and 750 (ArC–H (oop); dH (200 MHz, CDCl3)
3.28 (s, 1H, C^CH), 7.58 (br dd, 1H, J5–6Z7.8 Hz, J6–7
7.0 Hz, H-6), 7.73 (ddd, 1H, J7–8Z8.6 Hz, J6–7Z7.0 Hz,
J5–7Z1.6 Hz, H-7), 7.79 (dd, 1H, J5–6Z7.8 Hz, J5–7
Z
Z
1.6 Hz, H-5), 8.10 (br d, 1H, J7–8Z8.6 Hz, H-8), 8.29 (d,
1H, J2–4Z2.3 Hz, H-4), and 8.95 (d, 1H, J2–4Z2.3 Hz,
H-2); lmax(CH2Cl2)/nm 239 (3, 30,054), 282 (3, 7717), 316
(3, 3579), and 330 (3, 3659 L molK1 cmK1).
4.1.10. 2-Methyl-4-[-20-(80-chloroquinolyl)]-but-3-yn-2-
ol (10). Following the preparation of 7, a mixture of
2,8-dichloroquinoline (6) (367 g, 1.85 mmol), 2-methylbut-
3-yn-2-ol (0.2 mL, 2.02 mmol) in freshly distilled diethyl-
amine (2 mL) were added dichloro bis(triphenylphosphine)
palladium (37 mg, 0.05 mmol) and cuprous iodide (2 mg,
0.01 mmol). The mixture was stirred for 1 h at 40 8C, giving
2-methyl-4-[20-(80-quinolyl)]-but-3-yn-2-ol (10) (415 mg,
91%) as a yellow solid, mp 78–80 8C. dH (200 MHz, CDCl3)
C11H7N (153.18). Anal. Calcd C 86.25, H 4.61, N 9.14;
found: C 86.12, H 4.39, N 8.93.
4.1.13. 4-Ethynylquinoline (13). Following the preparation
of 11, 2-methyl-4-(40-quinolyl)but-3-yn-2-ol (9) (190 mg,
0.9 mmol) in dry toluene (2 mL), and powder of sodium
hydroxide (4 mg, 0.1 mmol) at reflux temperature for
30 min, gave 4-ethynylquinoline (13) as a white solid, mp
96–97 8C (103 mg, 75%). nmax(KBr)/cmK1 3187 (^C–H
st), 2088 (C^C st), 1579, 1560, 1503, 1464 and 1420
(C]C and C]N st conj.), 851, 811 and 803 (ArC–H (oop);
dH (200 MHz, CDCl3) 3.67 (s, 1H, C^CH), 7.53 (d, 1H,
1.67 (s, 6H, 2!CH3), 3.22 (s, 1H, OH), 7.44 (dd, 1H, J5–6
Z
8.6 Hz, J6–7Z7.8 Hz, H-6), 7.54 (d, 1H, J3–4Z8.6 Hz, H-3),
7.70 (dd, 1H, J5–6Z8.6 Hz, J5–7Z1.6 Hz, H-5), 7.83 (dd,
1H, J6–7Z7.8 Hz, J5–7Z1.6 Hz, H-7) and 8.11 (d, 1H,
J3–4Z8.6 Hz, H-4); dC (50 MHz, CDCl3) 31.2 (2!CH3),
64.9 (C–OH), 83.9 (ArC^C), 96.8 (ArC^C),125.1 (C-3),
126.6 (C-6), 126.9 (C-5), 128.3 (C-4a), 130.2 (C-7), 132.4
(C-8), 136.8 (C-4), 143.9 (C-8a) and 153.3 (C-2); m/z 245
(MC, 50), 230 (100), 202 (75), 188 (78) and 162 (28).
C14H12ONCl (245.70). Anal. Calcd C 68.44, H 4.92, N 5.70;
found: C 68.70, H 4.74, N 5.76.
J2–3Z4.5 Hz, H-3), 7.60 (ddd, 1H, J5–6Z8.3 Hz, J6–7
6.7 Hz, J6–8Z1.6 Hz, H-6), 7.74 (ddd, 1H, J7–8Z8.6 Hz,
J6–7Z6.7 Hz, J5–7Z1.6 Hz, H-7), 8.11 (dd, 1H, J5–6
Z
Z
8.3 Hz, J5–7Z1.6 Hz, H-5), 8.27 (dd, 1H, J7–8Z8.6 Hz,
J6–8Z1.6 Hz, H-8) and 8.87 (d, 1H, J2–3Z4.5 Hz, H-2);
lmax(CH2Cl2)/nm 302, 311 and 325.
4.1.11. 2-Ethynylquinoline 0(11). General method. To a
solution of 2-methyl-4-(2 -quinolyl)-but-3-yn-2-ol (7)
(379 mg, 1.79 mmol) in dry toluene (2 mL), under argon
atmosphere, was introduced powder of sodium hydroxide
(10 mg, 0.25 mmol) and refluxed for 1 h. Then, the reaction
mixture was filtered and the solvent was removed giving a
brown oil, which was purified by flash silica gel column
chromatography (hexane/ethylacetate, 3:1). The 2-ethynyl-
quinoline (11) (168 mg, 61%) was isolated as a yellow solid,
mp 46–47 8C. nmax(KBr)/cmK1 3172 (^C–H st), 2103
(C^C st), 1616, 1593, 1552, 1500, 1457 and 1422 (C]C
and C]N st conj.), 833 and 758 (ArC–H (oop); dH
(200 MHz, CDCl3) 3.25 (s, 1H, C^CH), 7.53 (d, 1H,
J3–4Z8.1 Hz, H-3), 7.54 (ddd, 1H, J5–6Z8.1 Hz, J6–7Z7.0 Hz,
J6–8Z1.6 Hz, H-6), 7.72 (ddd, 1H, J7–8Z8.6 Hz, J6–7Z7.0 Hz,
C11H7N (153.18). Anal. Calcd C 86.25, H 4.61, N 9.14;
found: C 86.41, H 4.39, N 9.15.
4.1.14. 8-Chloro-2-ethynylquinoline (14). Following the
preparation of 11, 2-methyl-4-[20(8-chloroquinolyl)]but-3-
yn-2-ol (10) (414 mg, 1.68 mmol) in dry toluene (10 mL)
and powder of sodium hydroxide (7 mg, 0.17 mmol) at
reflux temperature for 1 h, gave 8-chloro-2-ethynylquino-
line (14) as an orange solid, mp 92–95 8C (202 mg, 65%).
nmax(KBr)/cmK1 3199 (^C–H st), 2098 (C^C st), 1609,
1593, 1542, 1500, 1491 and 1422 (C]C and C]N st conj.),
834, 760 and 670 (ArC–H (oop); dH (200 MHz, CDCl3) 3.29
(s, 1H, C^CH), 7.47 (dd, 1H, J5–6Z8.1 Hz, J6–7Z7.0 Hz,