J. CHEM. RESEARCH (S), 1998 569
2-Phenyl-3,4,5,6-tetrahydro-5-pyrimidinol 5c.ÐColorless crystals,
mp 125 8C (decomp.) (from hexane±CH2Cl2); ꢃH 3.56 (2 H, dd,
J 12.7, 2.7), 3.73 (2 H, dd, J 12.7, 2.7 Hz), 4.45 (1 H, m), 7.48±7.98
(5 H, m); ꢃH (CD3OD, ꢃ 3.34) 3.55 (2 H, dd, J 13.0, 3.2), 3.70 (2 H,
dd, J 13.0, 2.7), 4.43 (1 H, tt, J 3.2, 2.7), 7.64 (2 H, t-like, J 8.0),
ꢀ
7.75 (1 H, t-like, J 8.0), 7.76 (2 H, d-like, J 8.0); m/z 176 (M , 30),
175 (M
ꢀ
1, 82), 104 (100%) (Found: C, 68.3; H, 6.9; N, 15.8.
10H12N2O requires C, 68.16; H, 6.86; N, 15.90%).
5,5-Dimethyl-2-phenyl-3,4,6-trihydropyrimidine
C
5d.ÐColorless
plates, mp 172±174 8C (from hexane±CH2Cl2); ꢃH 1.00 (6 H, s) 2.80
(1 H, br, NH), 3.12 (4 H, s), 7.37±7.39 (3 H, m), 7.64±7.67 (2 H,
d-like, J 6.8 Hz); ꢃH (CD3OD, ꢃ 3.34), 1.18 (6 H, s), 3.33 (4 H, s),
7.65 (2 H, t, J 7.6), 7.75±7.78 (3 H, m); ꢃC 24.4, 25.4 50.6,
ꢀ
ꢀ
127.5, 128.3, 128.7, 132.6, 157.8; m/z 188 (M , 28), 187 (M
1,
80%) (Found: C, 76.4; H, 8.5; N, 14.6. C12H16N2 requires C,
76.55; H, 8.57; N, 14.88%).
2-Phenyl-1,4- and/or -3,4-dihydroquinazoline 5e.ÐColorless
needles, mp 142±143 8C (from hexane±CH2Cl2, lit.10 mp 142 8C); ꢃH
4.70 (2 H, br s), 6.89 (1 H, br d, J 7.3), 7.00 (1 H, ddd, J 7.6, 7.3,
0.8), 7.07 (1 H, br d, J 7.6), 7.15 (1 H, br t, J 7.3), 7.34 (2 H, t-like,
J 7.0), 7.40 (1 H, t-like, J 7.0), 7.73 (2 H, br d, J 7.0 Hz); ꢃH
(CD3OD, ꢃ 3.34) 4.74 (2 H, s), 7.00±7.06 (3 H, m), 7.18 (1 H, td,
J 7.2, 1.5), 7.49 (2 H, t-like, J 7.6), 7.54 (1 H, t-like, J 7.6), 7.81 (2 H,
d-like, J 7.6 Hz); ꢃC 44.7, 120.3, 121.5, 124.4, 125.5, 126.5, 128.0,
Scheme 1
1
128.5, 129.3, 130.5, 135.4, 155.0; ꢄ~max/cm 3217, 1586, 758, 695;
1, 100) (Found: C, 80.8; H, 5.8; N,
13.4. C14H12N2 requires C, 80.74; H, 5.81; N, 13.45%).
ꢀ
m/z 208 (M , 58%), 207 (M
ꢀ
B instead of a hydrodiazepine ring. Then B transforms to
the ®nal product 5 via the norcaradiene C with elimination
of o-aminophenol.
Comparison of the heats of formation of 5b
(35.20 kcal mol 1) and 4 (62.82 kcal mol 1) calculated by the
PM3 method8 suggests that the formation of the product is
thermodynamically controlled.
2-Phenylquinazoline 8e.ÐColorless crystals, mp 98±99 8C (from
hexane±CH2Cl2, lit.11 mp 98±100 8C); ꢃH 7.52 (4 H, m), 7.85 (2 H,
t, J 7.6), 8.07 (1 H, d, J 7.6), 8.63 (2 H, d, J 7.6 Hz), 9.42 (1 H, s);
ꢃC 123.4, 126.9, 127.1, 128.4, 128.48, 128.50, 130.5, 133.9, 137.9,
ꢀ
150.6, 160.3, 160.9; m/z 206 (M
, 100), 179 (43%) (Found:
C, 81.5; H, 4.9; N, 13.5. C14H10N2 requires C, 81.53; H, 4.89;
N, 13.58%).
Although the rearrangements of troponoid to benzenoid
compounds are well known, a transformation of the former
to hydro-1,3-diazines is, so far as we are aware, new.
2-Phenyl-4-(3H)-quinazolone 9.ÐColorless needles, mp 240±
242 8C (from hexane±CH2Cl2, lit.12 mp 242.5±243.5 8C); ꢃH 7.51
(1 H, dd, J 7.8, 6.8), 7.59 (3 H, m), 7.80 (1 H, dd, J 8.1, 6.8), 7.85
(1 H, d, J 8.1), 8.27 (2 H, m), 8.34 (1 H, d, J 7.8 Hz), 11.74 (1 H,
br s); ꢃH (CD3OD, ꢃ 3.34) 7.59±7.70 (4 H, m), 7.83 (1 H, dd, J 7.8,
0.8), 7.91 (1 H, ddd, J 8.0, 7.8, 1.2), 8.09 (2 H, d-like, J 7.6), 8.29
(1 H, dd, J 8.0, 1.2 Hz); ꢃC 120.9, 126.3, 126.7, 127.4, 128.0, 129.0,
Experimental
Mps were determined with a Mitamura air-bath apparatus and are
uncorrected. Proton and 13C NMR spectra (SiMe4 as the internal
standard) were determined with Bruker AC-200, AM-400 and/or
ARX-400 spectrometers, IR spectra with a Perkin-Elmer System
2000 FT instrument and mass spectra with Shimazu QP-1000 and
JEOL JMS-DX 303 spectrometers. Unless otherwise stated the
spectra were taken in the following solvents/media: IR, KBr; 1H
(200 and 400 MHz) and 13C (100 MHz) NMR, CDCl3; mass spectra
at 70 eV by the electron impact method. X-ray data were collected
on an Enraf-Nonius CAD4F diractometer with monochromatized
Mo-Ka radiation and y±2y scans. The progress of most reactions
was followed by TLC using Merck Kieselgel 60F254. All synthetic
samples were puri®ed by column chromatography (SiO2 or neutral
Al2O3) and recrystallization.
1
131.6, 132.8, 134.9, 149.5, 151.7, 163.9; ꢄ~max/cm 1685; m/z 222
ꢀ
(M , 100%) (Found: C, 75.6; H, 4.5; N, 12.6. C14H10N2O requires
C, 75.66; H, 4.54; N, 12.60%).
We thank Dr. Hideki Saito (Saitama University) for his
helpful advice as to the measurement and analysis of the
single-crystal X-ray diraction analysis.
Received, 30th October 1997; Accepted, 22nd May 1998
Paper E/7/07825K
2-Phenylperimidine 5a.ÐA solution of benzo[b]cyclohepta[e][1,4]-
oxazine 1 (484 mg, 2.48 mmol) and 1,8-diaminonaphthalene 2a
References
(1.45 g, 9.22 mmol) in ethanol (5 ml) was heated at 80 8C for 20 h.
The solvents were evaporated in vacuo and the residue separated
by column chromatography (silica gel, benzene, CH2Cl2, AcOEt) to
give 5a, 76% yield, orange plates, mp 186±188 8C (from hexane±
CH2Cl2, lit.7 mp 183±184 8C); ꢃH (CD3OD, ꢃ 3.34) 6.62 (2 H, br d,
J 7.2), 7.09 (2 H, dd, J 8.1, 0.8), 7.16 (2 H, dd, J 8.1, 7.2), 7.53
(2 H, t-like, J 7.2), 7.58 (1 H, t-like, J 7.2), 7.89 (2 H, d-like,
J 7.2 Hz); ꢃC (CD3OD, ꢃ 49.0) 120.6, 122.5, 123.2, 127.2, 128.1,
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1
129.4, 129.8, 132.3, 135.5, 137.0, 156.9; ꢄ~max/cm 3188, 1636, 1595,
ꢀ
761, 699; m/z 244 (Mꢀ , 100), 166 (M
C6H5, 100%) (Found:
C, 83.6; H, 4.9; N, 11.4. C17H12N2 requires C, 83.58; H, 4.95;
N, 11.47%). Crystal data: 17H12N2, monoclinic, space group
6 K. Shindo, H. Wakabayashi, H. Miyamae, S. Ishikawa and
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C
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P21/a, a 9.377(6), b 14.749(5), c 9.249(6) A, ꢂ 101.85(4)8,
3
1
V 1252(2) A3, Z 4, ꢅ 1.29 g cm
F(000) 551.
,
ꢆ(Mo-Kꢀ) 0.721 cm
,
2-Phenyl-3,4,5,6-tetrahydropyrimidine 5b.ÐColorless crystals, mp
86±87 8C (from hexane±CH2Cl2, lit.9 mp 86±87.5 8C); ꢃH 1.86 (2 H,
quint., J 5.8), 3.49 (4 H, t, J 5.8), 7.32 (2 H, t-like, J 6.7), 7.37 (1 H,
t-like, J 6.7), 7.63 (2 H, d-like, J 6.7 Hz); ꢃH (CD3OD, ꢃ 3.34) 2.14
(2 H, quint., J 5.8), 3.62 (4 H, t, J 5.8), 7.62 (2 H, t, J 7.2 Hz),
7.71±7.75 (3 H, m); ꢃC 20.4, 41.8, 126.1, 128.2, 129.7, 137.0,
ꢀ
1
155.0; ꢄ~max/cm 3298, 1623, 781, 699; m/z 160 (M , 50), 159
ꢀ
(M 1, 100%) (Found: C, 75.1; H, 7.5; N, 17.4. C10H12N2 requires
C, 74.97; H, 7.55; N, 17.48%).