The Journal of Organic Chemistry
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(×2), 131.1, 136.1, 153.8, 171.9 ppm. IR (KBr): ν
̃
3421, 3065, 2963,
6cf: yellow oil. 1H NMR (500 MHz, CDCl3): δH 0.96 (t, J = 7.3 Hz,
3H), 1.39−1.48 (m, 2H), 1.69−1.77 (m, 2H), 2.94 (t, J = 7.3 Hz, 2H),
7.57 (dd, J = 8.2 and 6.9 Hz, 1H), 7.64 (dd, J = 8.2 and 6.9 Hz, 1H),
7.88 (d, J = 8.2 Hz, 1H), 7.92 (d, J = 8.7 Hz, 1H), 7.96 (d, J = 8.2 Hz,
1H), 8.03 (dd, J = 8.7 and 1.8 Hz, 1H), 8.51 (s with fine coupling,
1H) ppm. 13C NMR (125 MHz, CDCl3): δC 13.8, 22.3, 25.0, 38.6,
124.2, 127.0, 127.9, 128.9, 129.2, 129.4, 130.0, 132.3, 133.5, 136.2,
2874, 1775, 1711, 1597 cm−1. Mass (m/z, %): 324 (M+, 4), 269 (17),
268 (100), 267 (94), 120 (56), 119 (34), 92 (11), 91 (22), 77 (28),
57 (29). HRMS (ESI): 347.1380, calcd for C19H20N2O3Na [M + Na]+
347.1372.
Synthesis of 1-Naphthyl-2-phenylethane-1,2-dione (6ab) by
the Reaction of 5-Hydroxy-N,N′,5-triphenylimidazolidine-2,4-
dione (7a) with 1-Naphthyllithium (9b). Typical Procedure. To
the solution of 1-naphthyllithium (9b) prepared from BuLi (1.63 M in
hexane, 4.10 mL, 6.68 mmol) and 1-bromonaphthalene in dry THF
(10 mL), a solution of 5-hydroxy-N,N′,5-triphenylimidazolidine-2,4-
dione (7a) (1.01 g, 2.93 mmol) in dry THF (5 mL) was added
dropwise under a N2 atmosphere at −78 °C and stirred for 1 h. The
reaction mixture was poured into sat. aq. NH4Cl and then extracted
with AcOEt. The organic layer was washed with sat. aq. NaCl, dried
over anhydrous Na2SO4 and concentrated in vacuo. The crude product
was dissolved in CHCl3 (15 mL) including Et3N (catalytic amount),
stirred at 50 °C for 30 min and concentrated in vacuo. The residue was
rinsed with CHCl3 to remove N,N′-diphenylurea by filtration and the
filtrate was concentrated in vacuo. The residue was chromatographed
on silica gel and eluted with hexane−AcOEt (4:1) to give 6ab
(753 mg, 99% yield) as a yellow solid.
192.5, 203.7 ppm. IR (liquid film):ν
̃
2959, 1711, 1668, 1626 cm−1. Mass
(m/z, %): 240 (M+, 7), 156 (12), 155 (100), 127 (66), 126 (12).
HRMS (ESI): 263.1061, calcd for C16H16O2Na [M + Na]+ 263.1048.
6ag: yellow oil. 1H NMR (500 MHz, CDCl3): δH 2.40 (s, 3H), 7.22
(d, J = 7.8 Hz, 2H), 7.51−7.57 (m, 4H), 7.67 (t with fine coupling, J =
7.3 Hz, 1H), 8.08 (d with fine coupling, J = 7.3 Hz, 2H) ppm. 13C
NMR (125 MHz, CDCl3): δC 21.9, 87.1, 100.1, 116.1, 128.9 (×2), 129.6
(×2), 130.5 (×2), 131.7, 133.7 (×2), 134.8, 142.7, 178.6, 188.6 ppm. IR
(liquid film): ν
̃
Z 2186, 1679, 1657, 1601 cm−1. Mass (m/z, %): 248
(M+, 2), 192 (27), 144 (11), 143 (100), 115 (13), 105 (58), 77 (55).
HRMS (ESI): 271.0738, calcd for C17H12O2Na [M + Na]+ 271.0735.
6ak: yellow oil. 1H NMR (400 MHz, CDCl3): δH 1.31 (s, 9H), 7.50
(dd, J = 7.9 and 7.4 Hz, 2H), 7.64 (t with fine coupling, J = 7.4 Hz,
1H), 7.83 (d with fine coupling, J = 7.9 Hz, 2H) ppm. 13C NMR
(125 MHz, CDCl3): δC 26.2 (×3), 42.6, 128.9 (×2), 129.5 (×2),
132.9, 134.5, 195.4, 210.9 ppm. (lit.,3a 100 MHz, CDCl3 δC 26.2, 42.6,
6ab: pale-yellow granules melted at 103.0−104.0 °C (from CH2Cl2)
(lit.,20 101.5−102 °C). H NMR (400 MHz, CDCl3): δH 7.44−7.54
1
̃
128.9, 129.5, 132.8, 134.5, 195.4, 210.9 ppm). IR (liquid film): ν 2969,
1704, 1676, 1597 cm−1. Mass (m/z, %): 190 (M+, 3), 105 (100), 77
(51), 57 (23).
(m, 3H), 7.58−7.68 (m, 2H), 7.74 (ddd, J = 8.6, 6.8, and 1.3 Hz, 1H),
7.91 (dd, J = 7.3 and 1.2 Hz, 1H), 7.93 (d with fine coupling, J = 8.3
Hz, 1H), 8.03 (d with fine coupling, J = 8.3 Hz, 2H), 8.11 (d, J = 8.2
Hz, 1H), 9.31 (d with fine coupling, J = 8.6 Hz, 1H) ppm. 13C NMR
(125 MHz, CDCl3): δC 124.4, 125.9, 127.1, 128.5, 128.7, 129.0 (×2),
129.4, 129.9 (×2), 130.9, 133.3, 134.0, 134.7, 135.0, 135.9, 194.5,
Synthesis of 2-Oxo-2-naphthylethanoic Acid (8c) from 5-
Hydroxy-5-(2-naphthyl)-N,N′-diphenylimidazolidine-2,4-dione
(7c). Typical Procedure. NaOH in H2O (4 M, 3 mL) was added to
a solution of 5-hydroxy-5-(2-naphthyl)-N,N′-diphenylimidazolidine-
2,4-dione (7c) (1.16 g, 2.94 mmol) in MeOH (10 mL) at room
temperature and heated 50 °C for 1 h. The reaction mixture poured
into H2O and extracted with AcOEt to give organic layer including
N,N′-diphenylurea. The thus-obtained aqueous layer was acidified with
1N HCl, and then extracted with AcOEt. The AcOEt solution was
washed with sat. aq. NaCl, dried over anhydrous Na2SO4 and con-
centrated in vacuo. The residue was crystallized from hexane−CH2Cl2
to give 8c (525 mg, 89% yield) as a yellow solid.
8c: yellow granules melted at 92.0−93.0 °C (from AcOEt−hexane)
(lit.,21 92− 93 °C from xylene). 1H NMR (500 MHz, CDCl3): δH 7.59
(dd with fine coupling, J = 8.2 and 6.9 Hz, 1H), 7.68 (dd with fine
coupling, J = 8.2 and 6.9 Hz, 1H), 7.89 (d, J = 8.2 Hz, 1H), 7.93 (d, J =
8.7 Hz, 1H), 8.02 (d, J = 8.2 Hz, 1H), 8.18 (d with fine coupling,
J = 8.7 Hz, 1H), 8.95−9.17 (m, 1H), 9.09 (s, 1H) ppm. 13C NMR
(125 MHz, CDCl3): δC 124.4, 127.2, 127.8, 128.9, 129.0, 130.0, 130.3,
197.1 ppm. IR (KBr): ν
̃
3065, 1673, 1661, 1594, 1572 cm−1. Mass (m/
z, %): 260 (M+, 9), 156 (11), 155 (100), 127 (68), 126 (14), 105 (17),
77 (29). HRMS (ESI): 283.0740, calcd for C18H12O2Na [M + Na]+
283.0735.
According to the procedure described above, unsymmetrical
diketones 6ab, 6bc, 6bf, 6cf, 6ag and 6ak were synthesized by the
reaction of 5-hydroxy-5-(1-naphthyl)-N,N′-diphenylimidazolidine-2,4-
dione (7b) with phenyllithium (9a), 7b with 2-naphtyllithium (9c), 7b
with butyllithium (9f), 5-hydroxy-5-(2-naphthyl)-N,N′-diphenylimida-
zolidine-2,4-dione (7c) with butyllithium (9f), 5-hydroxy-5-(4-
methylphenyl)ethynyl-N,N′-diphenylimidazolidine-2,4-dione (7g)
with 9a, 5-tert-butyl-5-hydroxy-N,N′-diphenylimidazolidine-2,4-dione
(7k) with phenyllithium (9a), respectively. The yields were 88% for
6ab (from 7b with 9a), 83% for 6bc, 91% for 6bf, 97% for 6cf, 98% for
6ag, and 62% for 6ak.
̃
132.2, 135.2, 136.5, 163.3, 184.3 ppm. IR (KBr): ν 3062, 3006, 2964,
6bc: yellow granules melted at 140.0−141.5 °C (from CH2Cl2). 1H
NMR (500 MHz, CDCl3): δH 7.46 (dd, J = 8.0 and 7.6 Hz, 1H), 7.53
(dd, J = 8.2 and 7.1 Hz, 1H), 7.60−7.66 (m, 2H), 7.76 (dd with fine
coupling, J = 8.7 and 6.9 Hz, 1H), 7.88 (d, J = 8.2 Hz, 1H), 7.89 (d, J =
8.2 Hz, 1H), 7.92−7.98 (m, 3H), 8.11 (d, J = 8.0 Hz, 1H), 8.14 (dd
with fine coupling, J = 8.7 and 1.6 Hz, 1H), 8.48 (s, 1H), 9.37 (d, J =
8.7 Hz, 1H) ppm. 13C NMR (125 MHz, CDCl3): δC 123.9, 124.4,
126.0, 127.1, 127.1, 127.9, 128.8, 128.8, 129.1, 129.4 (×2), 129.9, 130.7,
131.0, 132.4, 133.4, 134.1, 135.2, 135.9, 136.3, 194.7, 197.1 ppm. IR
1747, 1653, 1616, 1588 cm−1. HRMS (ESI negative): 199.0345, calcd
for C12H7O3 [M − H]¯ 199.0395.
According to the procedure described above, 5-substituted 5-hydro-
xyimidazolidine-2,4-diones (7a, 7b, 7d, 7e, 7i and 7k) were
individually hydrolyzed to give the corresponding α-ketocarboxylic
acids 8a (98%), 8b (94%), 8d (78%), 8e (39%), 8i (84%), and 8k
(96%): for hydrolysis of 7e, 8e was produced along with 2-oxo-N-
phenyl-2-(2,4,6-trimethylphenyl)acetamide (14) (54%). Hydroxyimi-
dazolidinedione 7g was similarly hydrolyzed to give 5-(4-methyl-
phenyl)furan-2,3-dione in 80% yield instead of the expected keto
carboxylic acid (8g).
(KBr): ν
̃
3380, 3044, 1780, 1722, 1597 cm−1 Mass (m/z, %): 310 (M+,
11), 156 (12), 155 (100), 128 (11), 127 (97), 126 (20). HRMS (ESI):
333.0898, calcd for C22H14O2Na [M + Na]+ 333.0892.
1
8a: yellow oil. H NMR (500 MHz, CDCl3): δH 7.53 (dd, J = 8.2
6bf: yellow oil. 1H NMR (500 MHz, CDCl3): δH 0.97 (t, J = 7.3 Hz,
3H), 1.41−1.50 (m, 2H), 1.71−1.78 (m, 2H), 2.97 (t, J = 7.4 Hz, 2H),
7.53 (dd, J = 8.2 and 7.3 Hz, 1 H), 7.59 (ddd, J = 8.2, 6.9, and 1.1 Hz,
1H), 7.68 (ddd, J = 8.5, 6.9, and 1.4 Hz, 1 H), 7.87 (dd, J = 7.3 and 1.4
Hz, 1H), 7.92 (d with fine coupling, J = 8.2 Hz, 1H), 8.10 (d, J = 8.2
Hz, 1 H), 8.96 (d, J = 8.5 Hz, 1 H) ppm. 13C NMR (125 MHz,
CDCl3): δC 13.8, 22.4, 25.1, 38.6, 124.2, 125.7, 126.9, 128.1, 128.7,
and 7.6 Hz, 2H), 7.70 (td, J = 7.6 and 1.1 Hz, 1H), 8.23 (dd, J = 8.2
and 1.1 Hz, 2H), 9.77 (s, 1H) ppm. (lit.,21 CDCl3, δH 7.51 (t, J =
7.8 Hz, 2H), 7.65 (t, J = 7.8 Hz, 1H), 8.14 (d, J = 7.8 Hz, 2H), 12.47
(s, 1H) ppm). 13C NMR (125 MHz, CDCl3): δC 129.0 (x2), 130.9
̃
(x2), 131.7, 135.6, 163.8, 184.9 ppm. IR (liquid film): ν 3496, 1741, 1686,
1596 cm−1. HRMS (ESI negative): 299.0570, calcd for C16H11O6 [2M-
H]¯ 299.0556.
129.0, 131.1, 133.6, 134.1, 135.3, 195.6, 204.0 ppm. IR (liquid film): ν
̃
8b: colorless needles melted at 102.0−103.0 °C (from CH2Cl2−
hexane) (lit.,22 112−114 °C). 1H NMR (500 MHz, CDCl3): δH 7.51−
7.62 (m, 2H), 7.68 (dd, J = 8.2 and 6.9 Hz, 1H), 7.90 (d, J = 7.8 Hz,
1H), 8.12 (d, J = 7.3 Hz, 1H), 8.32 (d, J = 6.9 Hz, 1H), 8.93 (d, J =
8.7 Hz, 1H), 10.51−11.06 (m, 1H) ppm. 13C NMR (125 MHz,
2959, 1710, 1666 cm−1. Mass (m/z, %): 240 (M+, 89), 197 (16), 169
(19), 157 (11), 156 (100), 155 (99), 128 (95), 127 (97), 126 (94), 101
(44), 85 (16), 77 (50), 76 (14), 75 (25), 74 (12), 57 (31), 51 (14).
HRMS (ESI): 263.1037, calcd for C16H16O2Na [M + Na]+ 263.1048.
637
dx.doi.org/10.1021/jo202304x | J. Org. Chem. 2012, 77, 632−639