An unusual route for the regioselective acylation of polycyclic aromatic hydrocarbons: Nitrile oxide addition followed by isoxazoline degradation

Article abstract of DOI:10.1055/s-2000-7118

By treatment with a base such as sodium methoxide or surprisingly lithium aluminium hydride monocycloadducts 1a-c afforded the corresponding oximes 2a-c which were oxidized to ketones 3a-c by the Dess-Martin method. The same ketones 3a-c are obtained by r

Full text of DOI:10.1055/s-2000-7118

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1469
An Unusual Route for the Regioselective Acylation of Polycyclic Aromatic
Hydrocarbons: Nitrile Oxide Addition Followed by Isoxazoline Degradation
Antonino Corsaro, Ugo Chiacchio, Vito Librando, Venerando Pistarà,* Antonio Rescifina
Dipartimento di Scienze Chimiche, Università di Catania, viale A. Doria 6, I-95125 Catania, Italy
Fax +39(95)580138; E-mail: acorsaro@dipchi.unict.it
Received 18 February 2000; revised 19 May 2000
1a−c,e−h of mesitonitrile oxide to the above PAHs3,5 and
Abstract: By treatment with a base such as sodium methoxide or
N-PAHs,4 and to monocycloadduct 1d of acridine,7 we
surprisingly lithium aluminium hydride monocycloadducts 1a−c af-
found that, among the other results, ketones 3a−c can be
prepared by base-induced cleavage of the C−O bond or by
forded the corresponding oximes 2a−c which were oxidized to ke-
tones 3a−c by the Dess−Martin method. The same ketones 3a−c are
obtained by reductive ring opening of 1a−c with Raney-Ni. Mono- hydrogenolytic cleavage of the N−O bond of the dihy-
cycloadducts 1d−h also gave oximes 2d−h upon treatment with the
same bases, but complex reaction mixtures were obtained when
oximes 2d−h were subjected to oxidation or monocycloadducts
droisoxazole ring (Scheme 1).
Monocycloadducts 1a−c are stable upon exposure to con-
centrated hydrochloric acid and 50% sulfuric acid at room
temperature and to heat up to 100 °C, while they undergo
the scission of O-C5 bond of the dihydroisoxazole ring
when treated with bases such as sodium methoxide to give
the corresponding oximes 2a−c in very good yields
(Scheme 1, Table).
1d−h were subjected to reduction with Raney-Ni.
Key words: polycyclic aromatic hydrocarbons, hydrogenations,
ketones, oximes, oxidations, ring opening
In the last two decades, 1,3-dipolar cycloadditions of ni-
trile oxides with aromatics1 and heteroaromatics1,2 have
received a great deal of interest since these aromatics
show an unexpected dipolarophilic reactivity against any
possible chemical inactivity due to the high loss of aroma-
ticity involved in their cycloaddition processes.
The conversion of oximes 2a−c into the corresponding ke-
tones 3a−c cannot be accomplished by simple acidic or
basic hydrolysis, but only by oxidation methods among
which the Dess−Martin’s periodinane (DMP) procedure8
gave fair yields of ketones 3a−c (Scheme 1, Table).
Monocycloadducts 1a−c were subjected to catalytic hy-
drogenation with Raney-Ni or Pd-C and chemical reduc-
tion with lithium aluminium hydride, which latter has
surprisingly produced oximes 2a−c in good yields (Ta-
ble), thus acting as a base rather than a reducing agent,
probably because of the aromatization of the PAH ring.
The catalytic hydrogenation of 1a−c with Raney-Ni under
hydrogen atmosphere (30 psi) in methanol containing
aqueous boric acid, afforded good yields of the same ke-
tones 3a−c (Table), obtained by oxidation of oximes 2a−
c with DMP (Scheme 1).
Recently we investigated the behavior of some polycyclic
aromatic hydrocarbons3 (PAHs) and their aza-analogs4
(N-PAHs) towards nitrile oxides and found that pyrene,
anthracene, phenanthrene and perylene add mesitonitrile
oxide and its dichloro derivative to afford modest yields
of mono- and bis-cycloadducts. In the case of anthracene
the cycloaddition was site- and regioselective. By using
the technique of microwave irradiation the above cycload-
ditions afforded improved yields of products and in partic-
ular their reaction times were dramatically shortened.5
Some aza-analogs of phenanthrene, phenanthridine, 1,10-
, 4,7- and 1,7-phenanthroline, add to mesitonitrile oxide to
give low yields of the corresponding monocycloadducts;
4,7-phenanthroline also gives some other minor products
among which the bis-cycloadduct to a pyridine ring was
isolated. Phenanthridinone is obtained in the case of
phenanthridine from the non-isolable monocycloadduct.4
These ketones represent the final products of the reaction
sequence which involves the initial hydrogenolytic cleav-
age of the N−O bond to the transient imino alcohols 4a−c
and successively the dehydration and hydrolysis of the
imine group to give again aromatic PAHs (Scheme 2).
This synthetic strategy for aromatic ketones of PAHs ap-
pears very interesting because it allows one to obtain, un-
like traditional methods of aroylation of PAHs,9 an unique
ketone, which is the 1-substituted and not the 9-
substituted10 derivative in the case of anthracene.
The construction of the dihydroisoxazole ring on the C=C
double bond of PAHs offers an interesting possibility of
introducing one or two functions on a ring of these PAHs
through the well known cleavage of the dihydroisoxazole
N−O or C−O bond which have been extensively investi-
gated in the past years and leads to the conversion of the
dihydroisoxazole ring into α,β-unsaturated oximes or ke-
tones, β-hydroxy ketones and γ-amino alcohols.6
The catalytic hydrogenation with Pd-C in methanol (H2,
60 psi, 10 h) led to the isolation of the ketone 3b (82%) in
the case of 1b, while 1a and 1c gave 6 (65%) and 7 (60%)
(Figure), respectively (see Experimental). Ketone 6 is de-
rived cleanly from ketone 3a by further reduction of phe-
nyl rings having bonds with characteristic features of
double bonds, while 7 is derived from 1b by reduction of
By applying this synthetic methodology, which in our
hands has included the treatment with acidic, basic and re-
ducing agents, of previously reported monocycloadducts
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A. Corsaro et al.
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Reagents and conditions: i) NaOMe/MeOH, reflux; ii) LiALH4,/THF, 0 °C; iii) DMP/CH2Cl2, r.t.; iv) Raney-Ni/H2 (30 psi)/MeOH/H3BO3/
H2O, 8 h, r.t.
Scheme 1
the only two external phenyl rings, which maintains the droisoxazole ring and reduction of N-PAH nucleus. All
unchanged dihydroisoxazole ring.
these crude materials were not further separated because
they were not considered synthetically useful.
Also mocycloadducts of N-PAHs 1d−h are stable to acid-
ic reagents and they undergo the dihydroisoxazole ring
opening by treatment with sodium methoxide or lithium
aluminium hydride to give the corresponding oximes 2d−
h. These were resistant to acidic and basic hydrolysis and
gave complex reaction mixtures by oxidative methods.
When 1d−h were subjected to reduction with Raney-Ni or
1
Pd-C, complex reaction mixtures were obtained, the H
and 13C NMR spectra of which indicated the presence of
many products derived from the opening of the dihy-
Figure Structures of compounds 6 and 7
Table Yields of Oximes 2a-h and Ketones 3a-c
Reaction
Conditions
Product
Melting points were determined with a Kofler hot-stage apparatus
and are uncorrected. IR spectra were taken on a Perkin-Elmer Para-
gon 500 FT-IR Spectrometer using KBr discs, NMR spectra were
recorded on a Varian instrument at 200 or 500 MHz (1H) and at 50
or 125 MHz (13C) using TMS as internal standard and CDCl3 as sol-
vent. Elemental analyses were performed on a Carlo Erba Elemen-
tal Analyser 1106. TLC separations were performed on Merck silica
gel 60-F254 precoated aluminium plates. Preparative chromato-
graphic separations were conducted by means of flash chromatog-
2a 2b 2c 2d 2e 2f 2g 2h 3a 3b 3c
MeO−Na+/MeOH 96 97 91 86 92 81 87 86
-
-
-
-
-
-
LiAlH4/THF
DMP/CH2Cl2
83 88 77 73 74 75 77 70
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
60 62 54
80 84 78
Raney-Ni/MeOH -
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An Unusual Route for the Regioselective Acylation of Polycyclic Aromatic Hydrocarbons
1471
Scheme 2
raphy using Merck silica gel 60 (0.035−0.070 mm) with
cyclohexane/EtOAc mixtures as eluents. Monocycloadducts 1a−
c,e−h were obtained according to the previously reported cycload-
dition reactions3-5 of mesitonitrile oxide with PAHs and N-PAHs.
Physical and spectral data of monocycloadduct 1d7 will be reported
elsewhere.
1H NMR (CDCl3, 200 MHz): δ = 2.28 (s, 6 H, CH3), 2.39 (s, 3 H,
CH3), 7.03 (s, 2 H, Mes H), 7.75 (s, 1 H, pyrene H), 7.93−8.27 (m,
7 H, pyrene H), 9.50 (dd, 1 H, J = 1.2, 8.0 Hz, pyrene H), 9.56 (br
s, 1 H, OH).
13C NMR (CDCl3, 50 MHz): δ = 19.93 and 21.25 (CH3), 124.55,
125.05, 125.72, 125.78, 125.93, 126.26, 126.76, 128.05, 128.45,
128.57, 130.03, 130.13, 130.96, 131.37, 131.46, 135.79, 138.50 (ar-
omatic C), 157.15 (oxime C).
Conversion of 1a−h into Oximes 2a−h; General Procedure
Method A: To a solution of dihydroisoxazoles 1a−h (2 mmol) in an-
hyd MeOH (20 mL) was added a solution of 0.1 M MeONa in
MeOH (20 mL) and the resulting mixture was refluxed until the
starting material disappeared (ca. 30 min). After removal of the sol-
vent under reduced pressure, the residue was taken again with H2O
(30 mL), extracted with EtOAc (3 × 20 mL), dried (Na2SO4) and
concentrated under reduced pressure to give oximes 2a−h, which
were purified by chromatography and crystallized from EtOAc.
Anal. calcd for C26H21NO (363.4) C, 85.92; H, 5.82; N, 3.85.
Found: C, 86.01; H, 8.85; N, 3.91.
MS: m/z = 363 (M+· ), 362 (M − 1)+, 346 (M − 17)+, 201 (M − 162)+.
Mesityl(9-phenanthryl)methanone Oxime (2b)
Yield: 97% by treatment with MeONa; 88% by treatment with
LiAlH4; white crystals; mp 185−187 °C.
IR (KBr): ν = 3276, 1609 cm-1.
Method B: To a stirred solution of dihydroisoxazoles 1a−h
(2 mmol) in anhyd THF (20 mL) was added LiAlH4 (60 mmol) at
0 °C and the mixture was allowed to react under stirring until the
starting material had disappeared (4 h). After hydrolysis, the mix-
ture was diluted with CH2Cl2 and then the organic layer was washed
with H2O (20 mL), dried (Na2SO4) and concentrated under reduced
pressure to give oximes 2a−h, which were purified by chromatog-
raphy and crystallized from EtOAc.
1H NMR (CDCl3, 500 MHz): δ = 2.24 (s, 3 H, CH3), 2.27 (s, 6 H,
CH3), 6.85 (s, 2 H, Mes H), 7.41 (s, 1 H, phenanthrene H), 7.50 (t,
1 H, J = 7.5 Hz, phenanthrene H), 7.61 (t, 1 H, J = 7.5 Hz, phenan-
threne H), 7.67 (m, 2 H, phenanthrene H), 7.71 (d, 1 H, J = 7.5 Hz,
phenanthrene H), 8.13 (m, 1 H, phenanthrene H), 8.64 (d, 1 H,
J = 8.5 Hz, phenanthrene H), 8.71 (m, 1 H, phenanthrene H), 9.41
(br s, 1 H, OH).
13C NMR (CDCl3, 125 MHz): δ = 20.82 and 20.99 (CH3), 122.54,
122.81, 126.16, 126.57, 127.51, 127.88, 128.38, 128.97, 129.11,
129.17, 130.03, 130.80, 130.95, 131.65, 133.98, 137.73, 138.28 (ar-
omatic C), 156.00 (oxime C).
Conversion of Oximes 2a−c into Ketones 3a−c; General Proce-
dure
To a stirred solution of oximes 2a−c (1 mmol) in CH2Cl2 (20 mL)
saturated with H2O prior to use, DMP (1.1 mmol) was add at r.t. The
mixture was allowed to react under vigorous stirring until oximes
2a−c were consumed and then it was diluted with 5% aq Na2SO4 so-
lution (10 mL) followed by H2O (10 mL). The organic layer was
washed with H2O (20 mL), dried (Na2SO4) and then concentrated
under reduced pressure to give ketones 3a−c which were purified by
chromatography and crystallized from EtOAc.
Anal. calcd for C24H21NO (339.4) C, 84.92; H, 6.24; N, 4.13.
Found: C, 84.04; H, 6.35; N, 4.28.
MS: m/z = 339 (M+· ), 338 (M − 1)+, 322 (M − 17)+, 177 (M − 162)+.
Mesityl(1-anthryl)methanone Oxime (2c)
Yield: 91% by treatment with MeONa; 77% by treatment with
LiAlH4; white crystals; mp 153−155 °C.
IR (KBr): ν = 3280, 1609 cm-1.
Conversion of 1a−c into Ketones 3a−c; General Procedure
In a hydrogenation vessel a suspension of 1a−c (2 mmol), a spatula
tip (estimated ca. 400 mg) of Raney-Nickel, MeOH (15 mL), H2O
(3 mL) and H3BO3 (5 mmol) were placed. The vessel was mechan-
ically shaken for 3 h under a hydrogen atmosphere (30 psi). The
mixture was then filtered through Celite® into a separatory funnel
containing a 10% aq NaHCO3 solution (10 mL) and CH2Cl2
(20 mL). After separation, the aqueous layer was extracted with
CH2Cl2 (2 × 10 mL) and the combined organic layers were washed
with brine, dried (Na2SO4) and concentrated under reduced pressure
to yield crude ketones 3a−c which were crystallized from EtOAc.
Alternatively, cycloadducts 1a−c (2 mmol) and a spatula tip of Pd/
C (10%) were used under an hydrogen atmosphere (60 psi) for 10 h,
but only 1b gave the corresponding ketone 3b; surprisingly, cy-
cloadducts 1a and 1c gave compounds 6 and 7, respectively.
1H NMR (CDCl3, 200 MHz): δ = 2.25 (s, 6 H, CH3), 2.28 (s, 3 H,
CH3), 6.88 (s, 2 H, Mes H), 7.69−7.79 (m, 5 H, anthracene H), 8.09
(m, 1 H, anthracene H), 8.24 (m, 1 H, anthracene H), 8.40 (m, 1 H,
anthracene H), 9.20 (br s, 1 H, OH).
13C NMR (CDCl3, 50 MHz): δ = 20.85 and 21.0 (CH3), 126.73,
127.26, 128.63, 129.23, 132.46, 132.78, 133.16, 133.60, 134.27,
134.94, 135.11, 135.84, 135.90, 136.89, 138.85 (aromatic C),
157.09 (oxime C).
Anal. calcd for C24H21NO (339.4): C, 84.92; H, 6.24; N, 4.13.
Found C, 85.08; H, 6.31; N, 4.22.
MS: m/z = 339 (M+· ), 338 (M − 1)+, 322 (M − 17)+, 117 (M − 162)+.
Mesityl(acridin-1-yl)methanone Oxime (2d)
Yield: 86% by treatment with MeONa; 73% by treatment with
LiAlH4; white crystals; mp 160−162 °C.
Mesityl(pyren-4-yl)methanone Oxime (2a)
Yield: 96% by treatment with MeONa; 83% by treatment with
LiAlH4; white crystals; mp 164−166 °C.
IR (KBr): ν = 3280, 1607 cm-1.
IR (KBr): ν = 3276, 1610 cm-1.
1H NMR (CDCl3 200 MHz): δ = 2.18 (s, 6 H, CH3), 2.37 (s, 3 H,
CH3), 7.01 (m, 2 H, Mes H), 7.18 (dd, 1 H, J = 7.2, 1 Hz, acridine
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A. Corsaro et al.
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H), 7.59 (m, 3 H, acridine H), 7.82 (dd, 1 H, J = 1.5, 6.6 Hz, acridine
H), 8.05 (d, 1 H, J = 8.5 Hz, acridine H), 8.15 (s, 1 H, acridine H),
8.25 (dd, 1 H, J = 8.6, 1 Hz, acridine H), 10.21 (s, 1 H, oxime H).
13C NMR (CDCl3 50 MHz): δ = 19.78 and 21.26 (CH3), 125.86,
127.07, 127.92, 128.45, 129.00, 129.14, 129.25, 130.81, 131.29,
132.86, 135.37, 135.60, 136.68, 137.10, 138.52, 139.01, 148.53,
149.52 (aromatic C), 160.60 (C=O).
Anal. calcd for C22H19N3O (341.4) C, 77.40; H, 5.61; N, 12.31.
Found: c, 77.45; H, 5.56; N, 12.39.
MS: m/z = 341 (M+· ), 340 (M − 1)+, 324 (M − 17)+, 179 (M − 162)+.
Mesityl([1,7]phenanthrolin-6-yl)methanone Oxime (2h)
Yield: 86% by treatment with MeONa; 70% by treatment with
LiAlH4; white crystals; mp 240−242 °C.
IR (KBr): ν = 3276, 1610 cm-1.
1H NMR (CDCl3, 200 MHz): δ = 2.19 (s, 6 H, CH3), 2.22 (s, 3 H,
CH3), 6.83 (s, 2 H, Mes H), 7.60 (q, 2 H, phenanthroline H), 7.63 (s,
1 H, phenanthroline H), 8.42 (dd, 1 H, J = 8.6, 1.8 Hz, phenanthro-
line H), 8.91 (dd, 1 H, J = 4.6, 1.6 Hz, phenanthroline H), 9.00 (dd,
1 H, J = 4.6, 1.6 Hz, phenanthroline H), 9.49 (dd, 1 H, J = 7.8, 1.2
Hz, phenanthroline H), 11.10 (br s, 1H, oxime H).
Anal. calcd for C23H20N2O (340.4) C, 81.15; H, 5.92; N, 8.23.
Found: C, 81.21; H, 5.85; N, 8.31.
MS: m/z = 340 (M+· ), 339 (M − 1)+, 323 (M − 17)+, 178 (M − 162)+.
Mesityl([1,10]phenanthrolin-5-yl)methanone Oxime (2e)
Yield: 92% by treatment with MeONa; 74% by treatment with
LiAlH4; white crystals; mp 246−248 °C.
IR (KBr): ν = 3278, 1610 cm-1.
13C NMR (CDCl3, 50 MHz): δ = 20.39 and 20.80 (CH3), 121.94,
122.66, 123.46, 127.52, 128.67, 128.82, 129.90, 132.94, 133.38,
137.25, 137.38, 138.54, 149.30, 150.11, 150.94, 151.68 (aromatic
C), 162.48 (oxime C).
1H NMR (CDCl3, 200 MHz): δ = 2.20 (s, 6 H, CH3), 2.25 (s, 3 H,
CH3), 6.85 (s, 2 H, Mes H), 7.51 (dd, 1 H, J = 8.1, 4.5 Hz, phenan-
throline H), 7.64 (s, 1 H, phenanthroline H), 7.71 (dd, 1 H, J = 8.3,
4.5 Hz, phenanthroline H), 8.07 (dd, 1 H, J = 8.1, 1.8 Hz, phenan-
throline H), 8.98 (dd, 1 H, J = 4.5, 1.6 Hz, phenanthroline H), 9.08
(dd, 1 H, J = 4.5, 1.8 Hz, phenanthroline H), 9.65 (dd, 1 H, J = 8.3,
1.8 Hz, phenanthroline H), 11.08 (br s, 1 H, oxime H).
13C NMR (CDCl3, 50 MHz): δ = 20.34 and 21.12 (CH3), 122.32,
122.93, 125.43, 128.75, 130.91, 131.95, 134.27, 136.79, 137.28,
139.00, 150.16, 150.62 (aromatic C), 159.44 (oxime C).
Anal. calcd for C22H19N3O (341.4) C, 77.40; H, 5.61; N, 12.31.
Found: C, 77.49; H, 5.68; N, 12.35.
MS: m/z = 341 (M+· ), 340 (M − 1)+, 324 (M − 17)+, 179 (M − 162)+.
Mesityl(pyren-4-yl)methanone (3a)
Yield: 60% by oxidation with DMP; 80% by reduction with Raney-
Ni; white crystals; mp 203−205 °C.
IR (KBr): ν = 1673 (C=O) cm-1.
1H NMR (CDCl3, 200 MHz): δ = 2.26 (s, 6 H, CH3), 2.38 (s, 3 H,
CH3), 6.98 (s, 2 H, Mes H), 7.90−8.27 (m, 8 H, pyrene H), 9.55 (d,
1 H, J = 7.8 Hz, pyrene H).
Anal. calcd for C22H19N3O (341.4) C, 77.40; H, 5.61; N, 12.31.
Found: C, 77.52; H, 5.67; N, 12.37.
MS: m/z = 341 (M+· ), 340 (M - 1)+, 324 (M - 17)+, 179 (M - 162)+.
Mesityl([4,7]phenanthrolin-5-yl)methanone Oxime (2f)
Yield: 81% by treatment with MeONa; 75% by treatment with
LiAlH4; white crystals; mp 254−255 °C.
IR (KBr): ν = 3282, 1608 cm-1.
13C NMR (CDCl3, 50 MHz): δ = 19.93 and 21.15 (CH3), 124.76,
125.71, 125.95, 126.14, 126.35, 126.49, 126.72, 128.09, 128.70,
129.75, 130.75, 130.96, 131.37, 131.94, 134.76, 135.11, 138.01,
139.73 (aromatic C), 179.74 (C=O).
1H NMR (CDCl3, 200 MHz): δ = 2.15 (s, 6 H, CH3), 2.27 (s, 3 H,
CH3), 6.88 (s, 2 H, Mes H), 7.65 (dd, 1 H, J = 4.4, 8.4 Hz, phenan-
throline H), 7.74 (dd, 1 H, J = 4.6, 8.6 Hz, phenanthroline H), 8.05
(s, 1 H, phenanthroline H), 8.92 (d, 1 H, J = 8.5 Hz, phenanthroline
H), 9.03 (d, 1 H, J = 8.5 Hz, phenanthroline H), 9.05 (d, 1 H, J = 4.4
Hz, phenanthroline H), 9.14 (d, 1 H, J = 4.4 Hz, phenanthroline H),
11.13 (br s, 1H, oxime H).
13C NMR (CDCl3, 50 MHz): δ = 20.42 and 21.02 (CH3), 117.16,
122.06, 122.54, 122.63, 123.52, 128.79, 129.26, 131.84, 134.29,
134.49, 137.30, 149.54, 149.61, 151.12 (aromatic C), 159.78
(oxime C).
Anal. calcd for C26H20O (348.5) C, 89.62; H, 5.79. Found: C, 89.79;
H, 5.86.
MS: m/z = 348 (M+· ), 229 (M − 119)+, 147 (M − 201)+.
Mesityl(9-phenanthryl)methanone (3b)
Yield: 62% by oxidation with DMP; 84% by reduction with Raney-
Ni; 82% by reduction with Pd/C; white crystals; mp 171−173 °C.
IR (KBr): ν = 1674 (C=O) cm-1.
1H NMR (CDCl3, 500 MHz): δ = 2.22 (s, 6 H, CH3), 2.35 (s, 3 H,
CH3), 6.94 (s, 2 H, Mes H), 7.54 (t, 1 H, J = 7.5 Hz, phenanthrene
H), 7.60 (s, 1 H, phenanthrene H), 7.67−7.75 (m, 4 H, phenanthrene
H), 8.66 (d, 1 H, J = 8 Hz, phenanthrene H), 8.74 (d, 1 H, J = 5.5
Hz, phenanthrene H), 9.09 (s, 1 H, phenanthrene H).
Anal. calcd for C22H19N3O (341.4) C, 77.40; H, 5.61; N, 12.31.
Found: C, 77.48; H, 5.69; N, 12.29.
13C NMR (CDCl3, 125 MHz): δ = 19.97 and 21.13 (CH3), 122.54,
123.04, 126.81, 126.89, 126.97, 127.36, 128.27, 128.83, 129.65,
130.52, 131.23, 130.41, 134.95, 138.40 (aromatic C), 179.78
(C=O).
MS: m/z = 341 (M+· ), 340 (M − 1)+, 324 (M − 17)+, 179 (M − 162)+.
Mesityl([1,7]phenanthrolin-5-yl)methanone Oxime (2g)
Yield: 87% by treatment with MeONa; 77% by treatment with
LiAlH4; white crystals; mp 231−233 °C.
IR (KBr): ν = 3278, 1608 cm-1.
Anal. calcd for C24H20O (324.4) C, 88.85; H, 6.21. Found: C, 88.91;
H, 6.25.
1H NMR (CDCl3, 200 MHz): δ = 2.20 (s, 6 H, CH3), 2.25 (s, 3 H,
CH3), 6.85 (s, 2 H, Mes H), 7.51 (dd, 1 H, J = 8.1, 4.5 Hz, phenan-
throline H), 7.64 (s, 1 H, phenanthroline H), 7.71 (dd, 1 H, J = 8.3,
4.5 Hz, phenanthroline H), 8.07 (dd, 1 H, J = 8.1, 1.8 Hz, phenan-
throline H), 8.98 (dd, 1 H, J = 4.5, 1.6 Hz, phenanthroline H), 9.08
(dd, 1 H, J = 4.5, 1.8 Hz, phenanthroline H), 9.65 (dd, 1 H, J = 8.3,
1.8 Hz, phenanthroline H), 11.08 (br s, 1H, oxime H).
13C NMR (CDCl3 50 MHz): δ = 20.34 and 21.12 (CH3), 122.32,
122.93, 125.43, 128.75, 130.91, 131.95, 134.27, 136.79, 137.28,
139.00, 150.16, 150.62 (aromatic C), 159.44 (oxime C).
MS: m/z = 324 (M+· ), 205 (M − 119)+, 147 (M − 177)+.
Mesityl(1-anthryl)methanone (3c)
Yield: 54% by oxidation with DMP; 78% by reduction with Raney-
Ni; white crystals; mp179−181 °C.
IR (KBr): ν = 1660 (C=O) cm-1.
1H NMR (CDCl3, 200 MHz): δ = 2.19 (s, 6 H, CH3), 2.34 (s, 3 H,
CH3), 6.94 (s, 2 H, Mes H), 7.28 (m, 2 H, anthracene H), 7.50 (m, 2
H, anthracene H), 8.06 (m, 3 H, anthracene H), 8.47 (s, 1 H, an-
thracene H), 9.89 (s, 1 H, anthracene H).
Synthesis 2000, No. 10, 1469–1473 ISSN 0039-7881 © Thieme Stuttgart · New York

PAPER
An Unusual Route for the Regioselective Acylation of Polycyclic Aromatic Hydrocarbons
1473
13C NMR (CDCl3, 50 MHz): δ = 19.80 and 21.09 (CH3), 123.91,
125.59, 125.91, 127.01, 127.72, 128.56, 128.79, 129.05, 129.24,
131.37, 131.68, 132.38, 132.68, 134.58, 135.03, 137.89, 139.88 (ar-
omatic C), 179.84 (C=O).
MS: m/z = 345 (M+· ), 198 (M − 147)+, 184 (M − 161)+, 161 (M −
184)+, 147 (M − 198)+.
Acknowledgement
Anal. calcd for C24H20O (324.4) C, 88.85; H, 6.21. Found: C, 85.95;
H, 6.31.
MS: m/z = 324 (M+· ), 205 (M − 119)+, 147 (M − 177)+.
The authors are grateful to the E.U. from INTAS and Italian
M.U.R.S.T. for financial support.
Mesityl(4,5,9,10-tetrahydropyren-4-yl)methanone (6)
Yield 65%; white crystals; mp 161−163 °C.
IR (KBr): ν = 1692 (C=O) cm-1.
References
(1) Caramella, P.; Grünanger, P. In 1,3-Dipolar Cycloaddition
Chemistry; Padwa, A., Ed.; Wiley: New York, 1984, Vol. 1,
p 291.
(2) Corsaro, A.; Pistarà V. In Trends in Heterocyclic Chemistry;
1995, 4, 169.
1H NMR (CDCl3, 200 MHz): δ = 2.09 (s, 6 H, CH3), 2.28 (s, 3 H,
CH3), 2.87, (m, 4 H, tetrahydropyrene H), 3.21 (m, 2 H, tetrahydro-
pyrene H), 3.91 (dd, 1 H, J = 6, 2.4 Hz, tetrahydropyrene H), 6.74−
6.89 (m, 2 H, tetrahydropyrene H), 6.96 (s, 2 H, Mes H), 6.98−7.18
(m, 4 H, tetrahydropyrene H).
13C NMR (CDCl3, 50 MHz): δ = 19.05, 19.74 and 21.26 (CH3),
28.18, 28.41 and 30.40 (CH2), 125.77, 126.58, 126.74, 126.888,
127.25, 127.52, 128.00, 129.77, 130.33, 130.87, 132.76, 133.60,
134.72, 135.15, 135.22, 135.34, 137.73 (aromatic C), 197.65
(C=O).
(3) Corsaro, A.; Librando, V.; Chiacchio, U.; Pistarà, V.
Tetrahedron 1996, 52, 13027.
Librando, V.; Chiacchio, U.; Corsaro, A.; Gumina, G.
Polycyclic Arom. Compds. 1996, 11, 313.
(4) Corsaro, A.; Librando, V.; Chiacchio, U.; Pistarà, V.;
Rescifina, A. Tetrahedron 1998, 54, 9187.
(5) Corsaro, A.; Chiacchio, U.; Librando, V.; Fisichella, S.;
Pistarà, V. Heterocycles 1997, 45, 1567.
(6) Desimoni, G.; Faita, G. In Seminars in Organic Synthesis, XVI
Summer Scool “A.Corbella“; Polo Editoriale Chimico, 1991,
p 4, 9.
Anal. calcd for C26H24O (352.5) C, 88.60; H, 6.86%. Found: C,
88.62; H, 6.85.
MS: m/z = 352 (M+· ), 233 (M − 119)+, 147 (M − 205)+.
1-Mesityl-3a,4,5, 7,8,9,10,11b-octahydroanthra[1,2-d]isoxazole
(7)
Yield 60%; white crystals; mp 148−150 °C.
IR (KBr): ν = 2925, 2853, 1450, 1380 cm-1.
Grünanger, P.; Vita Finzi, P. In The Chemistry of Heterocyclic
Compounds; Taylor E. C. Ed.; Wiley Interscience: New York,
1991, Chapter 2.
Chiacchio, U.; Rescifina, A.; Romeo, G. In Targets in
Herocyclic Systems; Attanasi, O. A.; Spinelli, D., Eds.; SCI:
Roma, 1997, Vol. 1, p 225.
1H NMR (CDCl3, 200 MHz): δ = 1.20 (m, 1 H, CH2), 1.29 (m, 1 H,
CH2), 1.49 (m, 2 H, CH2), 1.56 (m, 2 H, CH2), 2.19 (s, 3 H, CH3),
2.26 (m, 1 H, CH2), 2.30 (s, 6 H, CH3), 2.31 (m, 1 H, CH2), 2.27 (m,
1 H, CH2), 2.73 (m, 1 H, CH2), 2.79 (m, 1 H, CH2), 2.88 (m, 1 H,
CH2), 4.48 (d, 1 H, J = 10.6 Hz, isoxazoline H-4), 5.16 (ddd, 1 H,
J = 10.6, 5.8, 2.8 Hz, isoxazoline H-5), 6.01 (s, 1 H, CH), 6.05 (s, 1
H, Mes H), 6.83 (s, 1 H, CH), 6.85 (s, 1 H, Mes H).
13C NMR (CDCl3, 50 MHz): δ = 18.52, 19.80, 21.10 (CH3), 23.15,
23.85, 28.72, 28.97, 29.68 (CH2), 53.75 (C-4 isoxazoline), 78.69
(C-5 isoxazoline), 125.60, 126.93, 128.03, 129.00, 135.06, 135.36,
135.37, 135.89, 138.32 (aromatic C), 159.08 (C=N).
(7) Corsaro, A.; Chiacchio, U.; Pistarà, V.; Rescifina, A.,
unpublished results.
(8) Dess, D. B.; Martin, J. C. J. Org. Chem. 1983, 48, 4155.
(9) Gore, P. M. Chem. Rev. 1955, 55, 229.
Olah, G. A. In Friedel-Crafts and Related Reactions; Wiley
Interscience: New York, 1963−1964, Vol. 1-4.
Clar, E. Polycyclic Hydrocarbons; Academic Press: New
York, 1964, Vol. 1.
(10) Gore, P. M.; Hoskins, J. A. J. Chem. Soc. 1964, 5666.
Anal. calcd for C24H27NO (345.5) C, 83.44; H, 7.88; N, 4.05.
Found: C, 83.52; H, 7.81; N, 4.09.
Article Identifier:
1437-210X,E;2000,0,10,1469,1473,ftx,en;Z01000SS.pdf
Synthesis 2000, No. 10, 1469–1473 ISSN 0039-7881 © Thieme Stuttgart · New York