K. Panda, C. Venkatesh, H. Ila, H. Junjappa
FULL PAPER
binol 7 derived from benzylic Grignard reagent could be obtained
as an analytically pure sample by column chromatography over sil-
ica gel with hexane/EtOAc (10:1) as eluent.
ArH) ppm. 13C NMR (100 MHz, CDCl3): δ = 20.2, 109.4, 113.8,
114.4, 120.6, 120.9, 123.6, 124.8, 125.1, 125.4, 126.4, 126.5, 126.6,
127.2, 127.7, 128.1, 129.5, 132.9, 134.7, 138.0, 160.7 ppm. IR
(KBr): ν = 2937, 2357, 1326, 750 cm–1. MS (m/z, %): 298 (100)
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1-Benzyl-2-[bis(methylthio)methylene]-1-hydroxyacenaphthene (7):
[M]+, 297 (40.1), 283 (91.3), 239 (57.4). C21H14S (298.40): C 84.53,
Yield 82% (1.45 g); red, viscous liquid; Rf = 0.35 (hexane/EtOAc,
H 4.73%; found C 84.42, H 4.81%.
1
8:2). H NMR (400 MHz, CDCl3): δ = 2.48 (s, 3 H, SCH3), 2.57
(s, 3 H, SCH3), 3.53 (d, J = 12.9 Hz, 1 H, CH), 3.62 (d, J = 12.9 Hz,
1 H, CH), 4.65 (br. s, 1 H, OH), 6.79 (d, J = 7.3 Hz, 1 H, ArH),
6.96–7.02 (m, 3 H, ArH), 7.23 (d, J = 6.8 Hz, 2 H, ArH), 7.46 (t,
J = 7.8 Hz, 1 H, ArH), 7.52 (t, J = 7.8 Hz, 1 H, ArH), 7.60 (d, J
= 8.0 Hz, 1 H, ArH) 7.69 (d, J = 8.2 Hz, 1 H, ArH) 8.42 (d, J =
7.3 Hz, 1 H, ArH) ppm. 13C NMR (100 MHz, CDCl3): δ = 16.8,
17.6, 48.0, 86.1, 118.9, 119.2, 121.7, 122.5, 124.5, 124.9, 126.1,
127.1, 127.3, 127.8, 128.6, 130.1, 131.5, 135.8, 143.3, 151.4 ppm.
General Procedure for Base-Induced Conjugate Addition of Arylace-
tonitriles and Active Methylene Ketones to 2. Preparation of Adducts
12a–b and 17a–b: A solution of the appropriate arylacetonitrile
(11a–b) or ketone (acetophenone/4-methoxyacetophenone/ace-
naphthenone) (5 mmol) was added dropwise at 0 °C over a period
of 15 min. to a stirred suspension of NaH (0.6 g, 60%, 10 mmol)
in DMF (10 mL), and the reaction mixture was further stirred at
0 °C for 45 min. A solution of 2 (5 mmol) in DMF (10 mL) was
then added dropwise, and the reaction mixture was further stirred
at room temperature for 8–10 h. It was then poured into saturated
NH4Cl solution (200 mL) and extracted with CHCl3 (3×50 mL).
The combined extracts were washed with water (3×50 mL), dried
(Na2SO4) and evaporated to give the 1,4-addition/elimination ad-
ducts in nearly quantitative yields. The crude adducts (12a–b) were
found to be unstable towards purification by column chromatog-
raphy over silica gel.
IR (CH Cl ): ν = 3049, 2916, 1678, 1498, 1423 cm–1. MS (m/z, %):
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2
2
364 (100) [M]+. C22H20OS2 (364.53): C 72.49, H 5.53%; found C
72.56, H 5.31%.
7-(Methylthio)fluoranthene (4a): Yield 72% (0.89 g); yellow crystals
(chloroform/hexane); m.p. 136 °C; Rf = 0.5 (hexane). 1H NMR
(400 MHz, CDCl3): δ = 2.16 (s, 3 H, SCH3), 7.23 (d, J = 8.0 Hz, 1
H, ArH), 7.31 (t, J = 7.3 Hz, 1 H, ArH), 7.59 (t, J = 7.3 Hz, 1 H,
ArH), 7.65 (t, J = 7.0 Hz, 1 H, ArH), 7.70 (d, J = 7.3 Hz, 1 H,
ArH), 7.81 (d, J = 5.4 Hz, 1 H, ArH), 7.83 (d, J = 5.1 Hz, 1 H,
ArH), 7.90 (d, J = 6.8 Hz, 1 H, ArH), 8.40 (d, J = 6.8 Hz, 1 H,
ArH) ppm. 13C NMR (100 MHz, CDCl3): δ = 15.3, 118.1, 120.1,
124.6, 124.8, 126.3, 126.9, 127.5, 127.6, 128.0, 129.6, 132.1, 135.0,
2-[2-Cyano-1-(methylthio)-2-phenylethylidene]acenaphthen-1-one
(12a): Crude adduct; Rf = 0.6 (hexanes/EtOAc, 9:1). 1H NMR
(400 MHz, CDCl3): δ = 2.39 (s, 3 H, SCH3), 3.72 (s, 1 H, CH),
7.30–7.39 (m, 3 H, ArH), 7.51 (d, J = 7.6 Hz, 2 H, ArH), 7.67 (t,
J = 8.0 Hz, 1 H, ArH), 7.71 (t, J = 7.8 Hz, 1 H, ArH), 7.86 (d, J
= 8.3 Hz, 1 H, ArH), 7.98 (d, J = 6.8 Hz, 1 H, ArH), 8.08 (d, J =
8.0 Hz, 1 H, ArH), 8.35 (d, J = 7.0 Hz, 1 H, ArH) ppm. 13C NMR
(100 MHz, CDCl3): δ = 16.05, 35.63, 118.14, 122.05, 123.91,
125.81, 126.61, 127.84, 128.07, 128.35, 129.13, 129.23, 130.09,
131.77, 132.52, 132.76, 133.69, 138.45, 147.24, 191.25 ppm. IR
136.0, 136.2, 136.7, 139.9 ppm. IR (KBr): ν = 3033, 2997, 1876,
˜
1630, 1441 cm–1. MS (m/z, %): 248 (100) [M]+, 234 (43.9), 233
(33.2), 215 (21.1), 202 (17.9), 201 (14.7), 189 (25.3). C17H12S
(248.34): C 82.22, H 4.87%; found C 82.10, H 4.92%.
8-Methyl-10-(methylthio)fluoranthene (4b): Yield 70% (0.91 g); yel-
low crystals (chloroform/hexane); m.p. 134–135 °C; Rf = 0.4 (hex-
(KBr): ν = 2875, 2241, 1672, 1597, 1425, 767 cm–1.
1
˜
anes). H NMR (400 MHz, CDCl3): δ = 2.49 (s, 3 H, CH3), 2.65
(s, 3 H, SCH3), 7.08 (s, 1 H, ArH), 7.57 (s, 1 H, ArH), 7.59–7.67
(m, 2 H, ArH), 7.80 (d, J = 8.0 Hz, 1 H, ArH), 7.83 (d, J = 8.0 Hz,
1 H, ArH), 7.91 (d, J = 6.8 Hz, 1 H, ArH), 8.35 (d, J = 6.8 Hz, 1
H, ArH) ppm. 13C NMR (100 MHz, CDCl3): δ = 15.5, 21.8, 119.4,
119.9, 124.0, 125.7, 125.8, 126.0, 126.9, 127.5, 128.1, 129.7, 132.4,
The adduct 17a was purified by column chromatography and char-
acterized by its spectral and analytical data. The adduct 17b from
4-methoxyacetophenone and the adduct from acenaphthenone
were used as such for further cyclization.
2-(1-Methylthio-3-oxo-3-phenylpropylidene)acenaphthen-1-one
(17a): Yield 91% (1.56 g); yellow solid (chloroform/hexane); m.p.
166–167 °C; Rf = 0.4 (8:2 hexanes/EtOAc). 1H NMR (400 MHz,
CDCl3): δ = 2.47 (s, 3 H, SCH3), 5.26 (s, 2 H, CH2), 7.51 (t, J =
8.0 Hz, 2 H, ArH), 7.58–7.64 (m, 3 H, ArH), 7.77 (d, J = 7.4 Hz,
1 H, ArH), 7.85 (d, J = 7.0 Hz, 1 H, ArH), 8.00 (d, J = 8.0 Hz, 1
H, ArH), 8.11 (d, J = 8.0 Hz, 2 H, ArH), 8.24 (d, J = 7.0 Hz, 1 H,
ArH) ppm. 13C NMR (100 MHz, CDCl3): δ = 14.0, 40.3, 121.3,
122.4, 122.8, 124.4, 127.5, 128.2, 128.7, 129.1, 130.0, 131.0, 133.4,
134.6, 136.4, 136.8, 137,8, 140.3 ppm. IR (KBr): ν = 1604, 1549,
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1434, 766 cm–1. MS (m/z, %): 262 (100) [M]+, 247 (22.7), 229 (17.9),
215 (13.3), 202 (18.3), 203 (14.0). C18H14S (262.37): C 82.40, H
5.38%; found C 82.23, H 5.49%.
7-Methyl-10-(methylthio)fluoranthene (4c): Yield 65% (0.85 g); yel-
low crystals (chloroform/hexane); m.p. 97–98 °C; Rf = 0.4 (hex-
1
anes). H NMR (400 MHz, CDCl3): δ = 2.61 (s, 3 H, SCH3), 2.71
(s, 3 H, CH3), 7.11 (d, J = 8.0 Hz, 1 H, ArH) 7.18 (d, J = 8.0 Hz,
1 H, ArH), 7.61 (t, J = 7.2 Hz, 1 H, ArH), 7.66 (t, J = 7.2 Hz, 1
H, ArH), 7.82 (d, J = 8.0 Hz, 2 H, ArH), 7.96 (d, J = 7.2 Hz, 1 H,
ArH), 8.48 (d, J = 7.2 Hz, 1 H, ArH) ppm. 13C NMR (100 MHz,
CDCl3): δ = 15.9, 20.2, 123.2, 124.7, 125.7, 126.4, 126.5, 127.6,
127.9, 129.5, 130.1, 131.4, 132.1, 132.2, 136.4, 136.6, 137.0,
133.7, 135.1, 136.5, 137.7, 151.3, 191.0, 195.3 ppm. IR (KBr): ν =
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3052, 2921, 1677, 1550, 769 cm–1. MS (m/z, %): 344 (100) [M]+.
C22H16O2S (344.43): C 76.72, H 4.68; N; found C 76. 64, H 4.76.
Procedure for Cycloaromatization of the Adducts 12a–b to 13a–b.
Synthesis of Benzo[j]fluoranthenes 13a–b: The crude adduct 12a (ca.
5 mmol) was mixed with PPA (25 mL), whereas the adduct 12b was
dissolved in H3PO4 (25 mL). Both reaction mixtures were heated
at 90–100 °C for 5–6 h (monitored by TLC). Each was then cooled,
poured into ice-cold water (150 mL) and extracted with CHCl3
(3×50 mL). The combined organic layers were washed with water
(3×50 mL) and dried over Na2SO4. The solvent was distilled off
to give crude products (13a or 13b), which were purified by column
chromatography with hexane/ethyl acetate (97:3) as eluent.
137.8 ppm. IR (KBr): ν = 1586, 1428, 1370, 770 cm–1. MS (m/z,
˜
%): 262 (100) [M]+, 247 (43.9), 229 (8.5), 215 (21.1), 203 (17.2),
202 (19.0). C18H14S (262.37): C 82.40, H 5.38%; found C 82.56, H
5.22%.
7-(Methylthio)benzo[k]fluoranthene (8): Yield 70% (1.04 g); yellow
solid (chloroform/hexanes); m.p. 147–148 °C; Rf = 0.90 (hexanes/
EtOAc, 8:2). 1H NMR (400 MHz, CDCl3): δ = 2.83 (s, 3 H, SCH3),
7.52 (dt, J = 7.4, 1.2 Hz, 1 H, ArH), 7.59–7.70 (m, 3 H, ArH), 7.83
(d, J = 8.0 Hz, 1 H, ArH), 7.84 (d, J = 8.3 Hz, 1 H, ArH), 7.95 (s,
1 H, ArH), 7.96 (d, J = 6.8 Hz, 1 H, ArH), 8.10 (d, J = 8.0 Hz, 1
8-Cyano-7-(methylthio)benzo[j]fluoranthene (13a): Yield 54 %
H, ArH), 8.43 (d, J = 7.0 Hz, 1 H, ArH), 8.76 (d, J = 8.2 Hz, 1 H, (0.87 g); orange solid (chloroform/hexanes); m.p. 223–224 °C; Rf =
Eur. J. Org. Chem. 2005, 2045–2055