6738 J. Am. Chem. Soc., Vol. 122, No. 28, 2000
Adam et al.
was cooled to 0 °C and then was added dropwise a solution of 14.1 g
(80.0 mmol) of dione 4 in 10 mL of dry THF. After complete addition
(ca. 30 min), the reaction mixture was stirred at 20 °C overnight and
worked up by adding 350 mL of a cold saturated NH4Cl solution. The
aqueous phase was extracted with ethyl ether (3 × 100 mL) and the
combined extracts were dried over anhydrous MgSO4. After evaporation
of the solvent (40 °C/760 Torr), the crude product was purified by
silica gel chromatography (SiO2, CH2Cl2) to afford 6.77 g (3.35 mmol,
42%) of a colorless oil.
IR (CCl4): V ) 3280 (CtC-H), 2950, 1700, 1645, 1530, 1050,
950 cm-1. 1H NMR (CDCl3): δ 1.47 (s, 3H), 1.49 (s, 3H), 2.48 (d, 4J
) 2.2 Hz, 1H), 4.68 (d, 4J ) 1.9 Hz, 1H), 7.48 (mc, 3H), 7.69 (d, 3J )
7.5 Hz, 2H). 13C NMR (CDCl3): δ 20.7 (q), 23.2 (q), 51.9 (s), 69.0
(d), 74.3 (d), 82.3 (s), 127.7 (d), 128.2 (d), 131.4 (d), 138,1 (s), 209.1
(s). Anal. Calcd for C13H14O2 (202.3): C, 77.20; H, 6.98. Found: C,
76.85; H, 6.79.
2,2-Dimethyl-1-phenylpent-4-ine-1,3-dione (6). Ten milliliters of
Jones reagent,14 prepared from a 1.6 M solution of CrO3 in 2.2 M
H2SO4, was added dropwise to a solution of 2.93 g (14.5 mmol) of 5
in 30 mL of acetone at 0 °C. The reaction mixture was stirred first for
30 min at 0 °C and subsequently for 7.5 h at 20 °C, diluted with 20
mL of distilled water, and extracted with ethyl ether (3 h, 10 mL). The
organic phase was washed with saturated NaHCO3 solution (10 mL)
and saturated NaCl solution (10 mL) and dried over anhydrous MgSO4.
The solvent was removed (40 °C/20 Torr), and silica gel chromato-
graphy (SiO2, CH2Cl2) gave 2.19 g (10.9 mmol, 75%) of a colorless
oil.
kept 3 d at -20 °C. For workup, 0.15 g of potassium carbonate and
0.30 g of silica gel were added, the suspension was stirred for 30 min
at ca. 20 °C, the solid was removed by filtration, and the solvent was
evaporated (ca. 20 °C/12 Torr). Purification of the crude product by
column chromatography (basic Al2O3, 5:5:1 CH2Cl2/petroleum ether/
ethyl acetate) afforded 230 mg (0.293 mmol, 60%) of a colorless
powder, mp 166-168 °C dec.
1
IR (KBr): V 3050, 2960, 2910, 1595, 1440, 1370, 1020 cm-1. H
NMR (CDCl3): δ )0.21, 0.28 and 0.34 (s, 9H), 1.01, 1.05 and 1.07
(s, 9H), 2.26 (mc, 6H), 3.69 (mc, 3H), 4.18 (mc, 3H), 5.53 (mc, 6H),
7.49 (mc, 9H), 7.80 (mc, 6H), 8.23 (mc, 3H). 13C NMR (CDCl3): δ
17.2 (q), 17.5 (q), 31.6 (t), 43.2 (d), 58.8 (d), 64.5 (s), 64.6 (s), 97.0
(s), 98.0 (s), 127.2 (d), 127.6 (d), 127.8 (d), 127.9 (d), 128.4 (d), 133.5
(s), 135.7 (2 × s). Anal. Calcd for C54H56N6 (787.1): C, 82.41; H,
6.91; N, 10.68. Found: C, 82.19; H, 7.54; N, 9.71. All attemps to obtain
a more satisfactory elemental analysis failed.
1,3,5-Tris-1′-{1′r,4′r,4a′r,7a′r)-4′,4a′,5′,6′,7′,7a′-hexahydro-8′,8′-
dimethyl-4′-phenyl-1′,4′-methano-1H-cyclopenta[d]pyridazine}-
benzene (3). A sample of 141 mg (0.180 mmol) of the trisazoalkane
9 was dissolved in 30 mL of benzene and ca. 15 mg of PtO2 catalyst
was added. The reaction mixture was deareated three times by
evacuation and flushing with hydrogen gas and saturated with the latter.
The hydrogenation was carried out at ca. 20 °C for 24 h under normal
pressure. The catalyst was removed by filtration and the solvent
evaporated (ca. 20 °C/10 Torr) to afford 136 mg (0.171 mmol, 95%)
of a colorless powder, mp 144-145 °C dec.
IR (CCl4): V 3280 (CtC-H), 2960, 1670, 1650, 1450, 1060, 960
IR (KBr): 2940, 2850, 1590, 1460, 1440, 1365, 1275, 1015 cm-1
.
1
cm-1. H NMR (CDCl3): δ 1.57 (s, 6H), 3.26 (s, 1H), 7.43 (mc, 3H),
UV (benzene): λmax (ꢀ) 329 nm (sh, 160), 351 (sh, 254), 362 (332). 1H
NMR (CDCl3): δ 0.16, 0.23 and 0.29 (s, 9H), 0.97, 1.03 and 1.09 (s,
9H), 1.58 (mc, 18H), 3.63 (mc, 6H), 7.46 (mc, 9H), 7.78 (mc, 6H), 8.06,
8.16 and 8.21 (s, 3H). 13C NMR (CDCl3): δ 17.3 (q), 18.0 (q), 25.4
(t), 25.5 (t), 28.7 (t), 48.8 (d), 49.0 (d), 66.6 (s), 98.2 (s), 98.5 (s), 98.7
(s), 126.4 (d), 127.5 (d), 127.7 (d), 128.3 (d), 136.2 (2 H, s). Anal.
Calcd for C54H60N6 (793.1): C, 81.78; H, 7.62; N, 10.59. Found: C,
81.62; H, 8.06; N, 10.01.
3
7.77 (d, J ) 7.0 Hz, 2H). 13C NMR (CDCl3): δ 22.7 (q), 61.4 (s),
79.5 (s), 82.6 (d), 128.6 (d), 129.0 (d), 133.0 (d), 135.2 (s), 188.1 (s),
197.5 (s). Anal. Calcd for C13H12O2 (200.2): C, 77.98; H, 6.04.
Found: C, 77.75; H, 6.09.
1,3,5-Tris[2′,2′-dimethyl-1′,3′-dioxo-3′-phenylpropyl]benzene (7).
Under an argon-gas atmosphere was added a sample of 88.7 µL (62.1
mg ≡ 0.849 mmol) of freshly distilled diethylamine to a stirred solution
of 1.30 g (6.49 mmol) of dione 6 in 10 mL of o-xylene and the mixture
was heated at reflux for 3 d. The solvent was removed (60 °C/80 Torr),
the residual brown oil was purified by silica gel chromatography (SiO2,
CH2Cl2), and recrystallization from MeOH gave 641 mg (1.07 mmol,
49%) of colorless needles, mp 108-109 °C.
IR (KBr): V 2970, 2905, 1670, 1650, 1580, 1430, 1240, 1210, 1150
cm-1. 1H NMR (CDCl3): δ 1.56 (s, 18H), 7.26 (mc, 9H), 7.65 (d, 3J )
7.1 Hz, 6H), 8.18 (s, 3H). 13C NMR (CDCl3): δ 24.9 (q), 59.3 (s),
128.6 (d), 129.0 (d), 132.6 (s), 133.0 (d), 135.3 (s), 136.6 (s), 198.7
(s), 198.9 (s). Anal. Calcd for C39H36O6 (600.7): C, 77.98; H, 6.04.
Found: C, 78.05; H, 6.13.
1,3,5,-Tris{3′-(4′,4′-dimethyl-5′-phenyl)-[4H]-pyrazole}benzene
(8). A solution of 501 mg (0.832 mmol) of the hexaketone 7 in 50 mL
of CHCl3 was treated with 208 mg (4.16 mmol) of 100% hydrazine
hydrate and kept at reflux for 16 h. The reaction mixture was allowed
to cool to ca. 20 °C and MgSO4 (ca. 0.5 g) was added. After filtration,
the solvent was removed (40 °C/20 Torr), and the crude product was
purified by silica gel chromatography (SiO2, 4:4:1 CH2Cl2/ethyl acetate/
petroleum ether) to afford 440 mg (0.747 mmol, 90%) of a light yellow
powder, mp 235-237 °C.
1,3,5-Tris-2′-(3′,3′-dimethyl-4′-phenyltricyclo[3.3.0.02′,4′]octanyl)-
benzene (10). A sample of 45.0 mg (0.0570 mmol) of the trisazoalkane
3 was dissolved in 0.6 mL of d6-benzene, degassed by purging with
argon gas, and irradiated (λ ) 333-364 nm, 1.3 W, ca. 10 min) until
1
complete consumption, as was confirmed by H NMR analysis. The
solvent was removed (40 °C/20 Torr) to yield 38.0 mg (0.0540 mmol,
94%) of colorless solid, mp 145-150 °C (mixture of diastereomers).
IR (KBr): 3055, 2944, 2844, 2857, 1602, 1590, 1496, 1444, 1386,
1024, 697 cm-1. 1H NMR (CDCl3): δ 0.58 and 0.62 (s, 9H), 1.44 and
1.47 (s, 9H), 1.57 (mc, 12H), 1.99 (mc, 6H), 2.63 (mc, 6H), 7.20 (mc,
18H). 13C NMR (CDCl3): δ 14.7 (q), 22.6 (q), 25.1 (t), 28.4 (t), 29.5
(s), 43.2 (d), 43.6 (d), 44.4 (d), 45.0 (d), 125.4 (d), 127.5 (d), 129.4
(d), 129.8 (d), 138.7 (s). Anal. Calcd for C54H60 (709.1): C, 91.47; H,
8.53. Found: C, 91.09; H, 8.57.
EPR Spectroscopy. A sample of ca. 2 mg (2.5 µmol) of the
trisazoalkane 3 was dissolved in 0.3 mL of toluene, placed into an
EPR sample tube (Ø ca. 2 mm), and thoroughly degassed by purging
with a slow stream of dry argon gas. The sample was sealed and the
77 K matrix was prepared by freezing the samples in liquid nitrogen.
The polyradical mixture was generated by irradiation with the 333-nm
line of an INNOVA-100 CW argon-ion laser (widened beam, 2.4 W,
1-60 min) at 77 K, and the EPR spectra were recorded on a Bruker
ESP-300 spectrometer (9.43 GHz), equipped with a variable-temperature
accessory and a data-acquisition system. All precautions were taken to
avoid undesirable spectral-line broadenings, such as those arising from
microwave saturation and magnetic-field overmodulation.
IR (KBr): V 2960, 2920, 1510, 1485, 1450, 1430, 1330, 1145 cm-1
.
1H NMR (CDCl3): δ 1.85 (s, 18H), 7.55 (mc, 9H), 8.14 (mc, 6H), 9.07
(s, 3H). 13C NMR (CDCl3): δ 22.9 (q), 58.9 (s), 128.1 (d), 128.8 (d),
129.0 (d), 129.6 (s), 131.0 (s), 131.2 (d), 177.8 (s), 180.0 (s). Anal.
Calcd for C39H36N6 (588.8): C, 79.56; H, 6.16; N, 14.27. Found: C,
79.28; H, 6.25; N, 13.90.
1,3,5-Tris-1′-{(1′r,4′r,4a′r,7a′r)-4′,4a′,7′,7a′-tetrahydro-8′,8′-
dimethyl-4′-phenyl-1′,4′-methano-1H-cyclopenta[d]pyridazine}-
benzene (9). A solution of 290 mg (0.493 mmol) of the 4H-pyrazole
8 in 30 mL of CH2Cl2 was cooled by means of an ice bath and 0.74
mmol of 100% CF3COOH and 5.0 mL of freshly distilled cyclopen-
tadiene were added. The mixture was stirred for 3 h at ca. 5 °C and
Acknowledgment. This work was supported by the Deutsche
Forschungsgemeinschaft, the Volkswagenstiftung, and the Fonds
der Chemischen Industrie.
(14) Bowden, K.; Heilbron, I. M.; Jones, E. R. H.; Weedon, B. C. L. J.
Chem. Soc. 1946, 39-48.
JA0003369