Pyrolysis of N-[1-(2-allyloxyphenyl)ethylidene]aniline 10.
(0.41 g, 1.6 mmol), 150–160 ЊC, 650 ЊC, 10Ϫ2 Torr, 2 h:
2-phenoxybenzonitrile 21 (R = H) (0.037 g, 12%); δH 7.66 (1H,
m), 7.50–7.34 (3H, m), 7.28–7.05 (4H, m) and 6.83 (1H, m)
[lit.,21 δH 7.6–7.8 (m)]; m/z 195 (Mϩ, 100%), 167 (53), 77 (66), 63
(17) and 51 (61): 2-(2-hydroxyphenyl)indole 27 (0.010 g, 3%);
δH(200 MHz) 9.28 (1H, s) and 7.72–6.85 (10H, m); m/z 209
(Mϩ, 100%), 180 (38), 152 (9), 105 (6), 89 (11), 77 (19) and 51
(9). The 1H NMR and mass spectra were identical with those of
an authentic sample prepared according to ref. 8 [δH 9.33 (1H, s)
and 7.71–6.84 (10H, m); m/z 209 (Mϩ, 100%), 180 (33), 152 (4),
105 (5), 89 (8), 77 (7), 63 (4) and 51 (2).]
7.65–6.85 (9H, m) and 2.33 (3H, s); δC 171.03 (q), 161.86 (q),
146.88 (q), 132.91, 128.93, 128.79, 124.66, 121.15, 119.63 (q),
118.12, 117.99 and 16.90; m/z 211 (Mϩ, 100%), 210 (61), 196
(82), 120 (22), 77 (73) and 51 (29)]: 2-phenoxybenzonitrile 21
(R = H) (0.042 g, 29%); δH 7.64 (1H, m), 7.50–7.35 (3H, m),
7.25–7.04 (4H, m) and 6.84 (1H, m); δC 159.66 (q), 154.94 (q),
134.05, 133.74, 129.98, 124.90, 122.66, 119.91, 116.88, 115.85
(q) and 103.65 (q) (spectra consistent with reported data21,22);
m/z 195 (Mϩ, 100%), 167 (31), 77 (45), 63 (5) and 51 (28) (1H
NMR and mass spectra are also identical with those previously
quoted): 2-(2-hydroxyphenyl)indole 27 (0.010 g, 6%); δH 9.36
(1H, s) and 7.72–6.83 (10H, m); m/z 209 (Mϩ, 100%), 180 (83),
1
Pyrolysis of N-(2-allyloxy-á-phenylbenzylidene)aniline 11.
(0.16 g, 0.52 mmol), 160–165 ЊC, 650 ЊC, 5 × 10Ϫ3 Torr, 30 min:
an initial insoluble compound, tentatively identified on account
of its mass spectrum as N-(1-hydroxyfluorenylidene)aniline 33
(R = H) (0.005 g, 4%), was filtered off before column chrom-
atography; m/z 271 (Mϩ, 51%), 270 (100), 254 (32) and 135 (28):
dibenzofuran 22 (R = H) (0.005 g, 6%); δH 7.96 (2H, m), 7.57
(2H, m), 7.45 (2H, m) and 7.34 (2H, m); m/z 168 (Mϩ, 100%),
152 (14), 105 (7), 89 (9) and 77 (12) (the H NMR and mass
spectra are consistent with those of the authentic sample previ-
ously quoted): 2-cyanophenol 19 (0.009 g, 10%); δH 7.60–7.34
(2H, m) and 7.05–6.94 (2H, m); m/z 119 (Mϩ, 100%), 91 (65)
and 77 (9) (the spectra are consistent with those previously
quoted).
Pyrolysis of 2-(4-methylphenoxy)benzophenone O-methyl-
oxime 17. (0.37 g, 1.17 mmol), 170–175 ЊC, 650 ЊC, 5 × 10Ϫ2
Torr, 1 h: 2-methyldibenzofuran 22 (R = Me) (0.019 g, 9%);
δH 7.96–7.23 (7H, m) and 2.51 (3H, s); δC 156.33 (q), 132.05 (q),
128.07, 127.03 (q), 126.79, 124.05 (q), 122.38, 120.49, 120.39,
111.49, 111.01 and 21.21 (one quaternary signal missing); m/z
183 (Mϩ, 48%), 182 (94), 181 (100), 168 (69), 154 (40) and 139
(14) (the spectra are consistent with those previously reported7):
2-(4-methylphenoxy)benzonitrile 21 (R = Me) (ca. 40%) δH 6.6–
7.7 (8H, m) and 2.36 (3H, s) [lit.,21 6.7–7.6 (8H, m) and 2.33
(3H, s)]; δC(CH and CH3 signals only) 130.41, 128.91, 128.58,
128.04, 122.25, 119.93 and 20.63; m/z 209 (Mϩ, 100%), 91 (60)
and 65 (23): 2-methyl-6-phenylphenanthridine 35 (R = Me) (0.04
g, 13%) (Found: Mϩ 269.1207; C20H15N requires M, 269.1205);
1
139 (69), 113 (12) and 84 (27). The H NMR spectrum was
identical with that of an authentic sample; [δH 7.98 (2H, m),
7.61 (2H, m), 7.48 (2H, m) and 7.36 (2H, m)]: N-(2-hydroxy-α-
phenylbenzylidene)aniline 32 (R = H) (0.028 g, 20%); δH 7.47–
6.74 (14H, m); m/z 273 (Mϩ, 46%), 272 (52), 196 (33), 181 (27),
180 (26) and 77 (100); spectra consistent with those of an
authentic sample11 [δH 14.53 (1H, br s) and 7.40–6.71 (14H, m);
δC 173.19 (q), 162.42 (q), 146.73 (q), 134.01 (q), 133.12, 132.12,
128.73, 128.65, 128.34, 128.02, 124.36, 122.28, 119.82 (q) and
117.87, m/z 273 (Mϩ, 100%), 272 (63), 196 (35), 181 (14), 180
(14) and 77 (53)]: 2-phenoxybenzonitrile 21 (R = H) (0.008 g,
8%) δH 7.65 (1H, m), 7.49–7.36 (3H, m), 7.28–7.05 (4H, m) and
6.85 (1H, m) (1H NMR spectrum is consistent with that quoted
in the previous paragraph): 6-(2-hydroxyphenyl)phenanthridine
34 (R = H) (0.02 g, 14%) (Found: Mϩ, 271.0991; C19H13NO
3
δH(360 MHz) 8.68 (1H, d, J 8.3), 8.39 (1H, s), 8.14 (1H, d,
3J 8.3), 8.07 (1H, dm, 3J 8.3), 7.83 (1H, ddd, 3J 8.3, 7.0, 4J 1.3),
7.73–7.70 (2H, m), 7.61–7.48 (5H, m) and 2.64 (3H, s);
δC 160.14 (q), 141.76 (q), 139.52 (q), 136.70 (q), 133.00
(q), 130.44, 130.23, 129.70, 129.57, 128.68, 128.47, 128.22,
126.81, 125.09 (q), 123.41 (q), 121.98, 121.40 and 21.85; m/z
269 (Mϩ, 68%), 268 (100), 253 (10), 196 (5), 119 (16), 91 (17)
and 77 (7).
3
requires M, 271.0997); δH(360 MHz) 8.69 (1H, d, J 8.2), 8.58
(1H, dd, 3J 8.1, 4J 1.1), 8.49 (1H, d, 3J 7.5), 8.09 (1H, dd, 3J 8.0,
4J 1.4), 7.90 (1H, ddd, 3J 8.2 and 7.1, 4J 1.2), 7.80–7.65 (4H, m),
7.40 (1H, ddd, 3J 7.8 and 7.3, 4J 1.5), 7.21 (1H, dd, 3J 7.8, 4J 1.5)
and 7.03 (1H, td, 3J 7.8, 4J 1.2); δC 158.97 (q), 157.71 (q), 145.98
(q), 141.16 (q), 134.58 (q), 131.51, 130.87, 128.97, 128.84,
128.60, 127.10, 127.02, 123.66 (q), 122.29, 121.78, 121.01 (q),
118.55 and 117.93 (one CH signal overlapping); m/z 271 (Mϩ,
56%), 270 (100), 241 (19), 151 (9), 135 (27) and 121 (17):
6-phenylphenanthridine 35 (R = H) (0.015 g, 11%); δH(360
Acknowledgements
We are most grateful to British Petroleum Ltd. for a PhD
Studentship (to M. B.). This investigation was also supported
by the University of Bologna (1997 Funds for selected research
topics).
3
3
4
MHz) 8.70 (1H, d, J 8.3), 8.62 (1H, dd, J 8.0, J 1.4), 8.26
(1H, dd, 3J 8.0, 4J 1.3), 8.10 (1H, d, 3J 8.4) and 7.90–7.50
(9H, m); δC 143.46 (q), 139.42 (q), 133.35 (q), 130.54, 130.05,
129.60, 128.85, 128.77, 128.65, 128.30, 127.75 (q), 127.04,
126.87, 125.68 (q), 123.63 (q), 122.07 and 121.83; m/z 255
1
References
(Mϩ, 58%), 254 (100) and 127 (29). The H NMR and mass
spectra of this compound are identical with those of an authen-
1 M. Black, J. I. G. Cadogan and H. McNab, J. Chem. Soc., Chem.
Commun., 1990, 395.
2 M. Black, J. I. G. Cadogan, H. McNab, A. D. MacPherson, V. P.
Roddam, C. Smith and H. R. Swenson, J. Chem. Soc., Perkin Trans.
1, 1997, 2483.
3 J. I. G. Cadogan, H. S. Hutchison and H. McNab, J. Chem. Soc.,
Perkin Trans. 1, 1991, 385.
4 J. I. G. Cadogan, C. L. Hickson and H. McNab, Tetrahedron, 1986,
42, 2135.
5 G. Calestani, R. Leardini, H. McNab, D. Nanni and G. Zanardi,
J. Chem. Soc., Perkin Trans. 1, 1998, 1813.
6 R. Leardini, H. McNab, D. Nanni, S. Parsons, D. Reed and A. G.
Tenan, J. Chem. Soc., Perkin Trans. 1, 1998, 1833.
7 J. I. G. Cadogan, H. S. Hutchison and H. McNab, Tetrahedron,
1992, 48, 7747.
8 V. K. Mahesh, M. Maheswari, R. Sharma and R. Sharma, Can. J.
Chem., 1985, 63, 632.
9 L. Cazaux and P. Tisnès, J. Heterocycl. Chem., 1976, 13, 665.
10 K. Bird, A. W. K. Chan and W. D. Crow, Aust. J. Chem., 1976, 29,
2281.
3
tic sample12 [δH(360 MHz) 8.69 (1H, d, J 8.3), 8.61 (1H, dd,
4
3
4
3
3J 8.0, J 1.4), 8.26 (1H, dd, J 8.2, J 1.3), 8.09 (1H, d, J 8.3)
and 7.85–7.50 (9H, m); m/z 255 (Mϩ, 54%), 254 (100) and 127
(16)].
Pyrolysis of 2-phenoxybenzaldehyde O-methyloxime 15. (0.69
g, 3 mmol), 90 ЊC, 650 ЊC, 5 × 10Ϫ3 Torr, 1 h: 2-cyanophenol 19
(0.21 g, 60%) mp 93–94 ЊC (lit.,19 93–96 ЊC) (spectroscopic data
as reported above): 2-phenoxybenzonitrile 21 (R = H) (0.07 g,
12%) as an oil, [lit.,21 bp 142 ЊC (3 Torr)]; m/z 195 (Mϩ, 100%),
167 (60), 77 (58) and 51 (36) (other spectra consistent with those
reported in other sections of this paper): dibenzofuran 22
(R = H) (trace) spectra as above.
Pyrolysis of 2Ј-phenoxyacetophenone O-methyloxime 16.
(0.18 g, 0.75 mmol), 150–160 ЊC, 650 ЊC, 10Ϫ2 Torr, 30 min:
N-[1-(2-hydroxyphenyl)ethylidene]aniline 28 (0.009 g, 6%);
δH 7.71–6.84 (9H, m) and 2.33 (3H, s); m/z 211 (Mϩ, 92%), 210
(76), 196 (100), 120 (25), 77 (74), 65 (10), 51 (30) and 39 (13),
spectra identical with an authentic sample9 [δH 14.65 (1H, br s),
11 C. Graebe and F. Keller, Ber. Deutsch. Chem. Ges., 1899, 32,
1683.
J. Chem. Soc., Perkin Trans. 1, 1998
1831