Notes
J . Org. Chem., Vol. 61, No. 17, 1996 6029
enjoyed by symmetrical 1,2-diazines,9 the azadiene 4 is
enabled by peculiar electronic and geometrical features
to enter the baggage of organic chemists as an effective
tool for one-pot syntheses of vicinal unsaturated dicyano
cage compounds.
Sch em e 3
Exp er im en ta l Section
Gen er a l P r oced u r es. Melting points are uncorrected. IR
spectra were measured for dispersions in KBr, while 1H and 13C
NMR spectra were recorded in CDCl3 solutions at 200 and 50
MHz, respectively. Silica gel plates (Merck F254; 0.2 mm) and
silica gel (ICN; 32-63, 60 A) were used for analytical and flash
chromatographies, respectively.
Th er m a l Rea ction s of 4,5-Dicya n op yr id a zin e (4)10 w ith
th e Dien es 2, 15a -c, a n d 19a -c: Syn th esis of Com p ou n d s
9, 16-18, a n d 20a -c. Gen er a l P r oced u r e. A mixture of 4
(1 mmol) and the reagent (5 mmol) in CHCl3 (1 mL) was heated
in a sealed tube (Pyrex, no. 13) at 110 °C until the starting
material disappeared (TLC, 1H NMR). Unless otherwise indi-
cated, the residue left by evaporation to dryness under reduced
pressure was simply washed with a small amount of n-pentane,
and analytical samples were obtained by crystallization from
ether.
Sch em e 4
A. 7,8-Dicyanotetracyclo[7.3.0.02,605,10]dodec-7-ene (9)11 (0.206
g, 98%): colorless needles; mp 225-226 °C; IR 2971, 2951, 2934,
1
2880, 2215, 1611 cm-1; H NMR δ 1.55-1.89 (m, 8H), 2.01 (br
s, 4H), 2.64 (m, 2H); 13C NMR δ 25.5 (t), 40.9 (d), 46.4 (d), 114.7
(s), 128.2 (s). Anal. Calcd for C14H14N2: C, 79.97; H, 6.71; N,
13.32. Found: C, 79.67; H, 6.65; N, 13.46.
B. The crude reaction product of 4 with 15a was subjected
to flash chromatography [40-70 °C petroleum ether/ethyl
acetate (7:1 v/v) as eluent] to give 3,4-dicyanotricyclo[3.3.1.02,7]-
non-3-ene (16)12 (Rf ) 0.32, 0.12 g, 71%) as a colorless crystalline
solid: mp 150 °C; IR 2963, 2870, 2215, 1597 cm-1 1H NMR δ
;
1.11 (d, J ) 8.8 Hz, 1H), 1.24 (m, 2H), 1.96 (dd, J ) 13.2 and
4.0 Hz, 2H), 2.35 (m, 3H), 3.35 (br s, 1H), 3.58 (m, 1H); 13C NMR
δ 31.7 (t), 33.7 (d), 36.6 (d), 36.8 (t), 40.1 (d), 114.5 (s), 114.9 (s),
126.15 (s), 134.2 (s). Anal. Calcd for C11H10N2: C, 77.62; H,
5.92; N, 16.46. Found: C, 77.37; H, 5.97; N, 16.18.
C. 8,9-Dicyanotricyclo[4.3.1.03,7]dec-8-ene (17)12 (0.18 g,
98%): colorless crystals; mp 107 °C; IR 2956, 2876, 2217, 1599
cm-1 1H NMR δ 1.51 (AB system, J AB ) 13.2 Hz, 4H), 1.53-
;
1.60 (m, 2H), 1.90-1.97 (m, 2H), 2.06-2.09 (m, 2H), 2.79 (t, J
) 4.2 Hz, 1H), 2.87 (quintet, J ) 2.7 Hz, 1H); 13C NMR δ 31.1
(t), 33.7 (d), 35.05 (d), 36.4 (t), 46.0 (d), 114.2 (s), 114.8 (s), 128.95
(s), 132.7 (s). Anal. Calcd for C12H12N2: C, 78.23; H, 6.57; N,
15.20. Found: C, 77.93; H, 6.76; N, 15.40.
Sch em e 5
D. 9,10-Dicyanotricyclo[5.3.1.03,8]undec-9-ene (18)12 (0.192 g,
97%): colorless needles; mp 154-155 °C; IR 2943, 2856, 2219,
1
1595 cm-1; H NMR δ 1.35-1.70 (m, 10H), 1.80-1.98 (m, 2H),
2.57 (t, J ) 3.0 Hz, 1H), 2.98 (quintet, J ) 2.9 Hz, 1H); 13C NMR
δ 13.5 (t), 28.2 (t), 29.0 (d), 29.4 (t), 35.1 (d), 43.35 (d), 114.4 (s),
132.1 (s), 133.2 (s). Anal. Calcd for C13H14N2: C, 78.75; H, 7.12;
N, 14.13. Found: C, 78.60; H, 7.23; N, 14.21.
E. Chromatographic workup (ethyl acetate as eluent) of the
2
crude reaction product of 4 with 19a afforded 5-acetyl-9,10-
dicyano-5-azatricyclo[5.3.1.03,8]undec-9-ene (20a )12 (Rf ) 0.22,
0.207 g, 86%) that was crystallized from the same solvent as
ivory-colored needles: mp 233-234 °C; IR 2957, 2935, 2861,
The structures of the new products 9, 14, 16-18, and
20a -c were determined from analytical and spectral
evidence (Experimental Section). In particular, the dif-
ferent cage frameworks exhibit highly diagnostic 13C
NMR patterns:8 while the spectrum of the tetracyclic
system 9 shows only five signals according to a C2v
symmetry, those of compounds 16-18 are characterized
by nine resonances due to a common Cs symmetry.
Likewise, 20b and 20c give rise to eight and nine signals,
respectively, but 13 absorptions are present in the
spectrum of 20a , the above symmetry being destroyed
by the amide moiety.
1
2218, 1631 cm-1; H NMR δ 1.24-1.37 (m, 2H), 1.57-1.79 (m,
2H), 1.86-2.01 (m, 2H), 2.12 (s, 3H), 2.56 (br d, J ) 13.5 Hz,
1H), 2.79 (t, J ) 3.0 Hz, 1H), 2.94 (quintet, J ) 2.5 Hz, 1H),
3.16 (br d, J ) 13.2 Hz, 1H), 3.72 (br d, J ) 13.5 Hz, 1H), 4.64
(br d, J ) 13.2 Hz, 1H); 13C NMR δ 21.6 (q), 29.1 (t), 29.4 (t),
29.5 (d), 29.8 (d), 34.75 (d), 41.3 (d), 44.2 (t), 49.4 (t), 113.9 (s),
131.2 (s), 133.0 (s), 170.6 (s). Anal. Calcd for C14H15N3O: C,
69.69; H, 6.27; N, 17.41. Found: C, 69.83; H, 6.32; N, 17.14.
F . 9,10-Dicyano-5-oxatricyclo[5.3.1.03,8]undec-9-ene (20b)12
(0.196 g, 98%): ivory-colored crystals; mp 110-111 °C; IR 2959,
(9) Ho, T.-L. In Symmetry: A Basis for Synthesis Design; J . Wiley
& Sons Inc.: New York, 1995; Chapter 9, p 474.
(10) Di Stefano, L.; Castle, R. N. J . Heterocycl. Chem. 1968, 5, 53-
59.
In conclusion, our findings open new perspectives in
the pyridazine chemistry, and despite the low reputation
(11) This product was numbered as the corresponding tetraester 3.4
(12) Beilstein’s names were adopted for the tricyclic cage systems.
(8) Isochronism was observed for the CN groups of 18, 20a , and 20b.