Vol. 26, No. 12, 2015
Buske et al.
2509
and copper(II) nitrate (4.53 g, 18.8 mmol), under magnetic
stirring and argon atmosphere. The mixture was stirred for
OH), 8.8 (s, 1H, CH=N) 8.62 (d, 1H, J 9.4 Hz, CH), 8.28
(d, 1H, J 8.2 Hz, CH), 8.24 (d, 2H, J 7.8 Hz, 2 × CH), 8.16
(d, 1H, J 9.0 Hz, CH), 8.14 (d, 1H, J 8.6 Hz, CH), 8.08 (d,
1H, J 9.0 Hz, CH), 8.03 (t, 1H, J 7.4, 7.8 Hz, CH), 7.99
(d, 2H, J 8.6 Hz, 2 × CH), 7.88 (d, 1H, J 8.2 Hz, CH),
24 h at 55 °C and a yellow precipitate was formed. After
this reaction time, the flask was cooled at room temperature
and the inorganic materials were filtered off. The product
obtained from the filtration was recrystallized from an
ethanol/ethyl acetate mixture (1:1; v/v) and the pale yellow
crystals collected were dried in an oven at 40 °C for 6 h,
yielding 2.75 g (89% yield); mp obtained: 150-151 °C
1
3
6.97 (d, 2H, J 8.2 Hz, 2 × CH); C NMR (100 MHz,
DMSO-d ) d 161.41, 161.31, 145.96, 131.55, 131.50,
6
131.40, 128.44, 127.78, 127.23, 126.81, 126.68, 126.35,
125.36, 125.25, 125.08, 124.58, 123.51, 116.28; HRMS
+
(ESI, TOF) m/z calcd. for C H NO [M + H] : 322.1226,
23 16
6
0
−1
(
mp lit.: 151-152 °C); IR (KBr) n / cm 2922-3043
max
(
1
C-H aromatic), 1592 (C=C), 1556 ( NO ), 1509 (C=C),
found: 322.1223.
as
2
1
309-1384 ( NO ); H NMR (400 MHz, DMSO-d ) d 8.72
s
2
6
(
(
(
(
d, 1H, J 8.6 Hz, CH), 8.70 (d, 1H, J 8.2 Hz, CH), 8.51
d, 1H, J 7.4 Hz, CH), 8.50 (d, 1H, J 9.4 Hz, CH), 8.49
d, 1H, J 7.4 Hz, CH), 8.44 (d, 1H, J 9.0 Hz, CH), 8.42
d, 1H, J 8.2 Hz, CH), 8.31 (d, 1H, J 9.0 Hz, CH), 8.23 (t,
4-Triisopropylsilyloxybenzaldehyde (7)
4-Hydroxybenzaldehyde (0.427 g, 3.5 mmol) was
dissolved in DMF (9 mL) in a 100 mL round-bottomed
flask in an argon atmosphere. Imidazole (0.483 g, 7 mmol)
and TIPS-Cl (1.0 g, 5.2 mmol) were then added and the
mixture was stirred at room temperature. After 12 h,
100 mL of water was added to the reaction mixture and
the organic fraction was extracted with n-hexane (1:1, v/v).
The combined organic layers were washed with brine, dried
1
H, J 7.4 Hz, CH).
1
-Aminopyrene (5)
1
-Nitropyrene (1.00 g, 4.0 mmol) and tin(II) chloride
dihydrate (4.35 g, 19.2 mmol) were mixed with 60 mL
of ethyl acetate in a 250 cm three-neck round-bottomed
3
over MgSO and the solid was filtered off. The solvent was
4
flask, under magnetic stirring and argon atmosphere.
The suspension mixture was heated to reflux for 6 h.
Subsequently, the solution was cooled at room temperature,
a sodium carbonate aqueous solution (20%; m/v) was added
to obtain pH ca. 8.0, and stirring was continued for 1 h.
The organic phase was then extracted three times with ethyl
acetate and dried with magnesium sulfate. The solid was
filtered-off and the solvent was evaporated, resulting in
removed by rotary evaporation and the residue was purified
by flash column chromatography (3:1 n-hexane/EtOAc),
yielding 0.747 g (76% yield) of the product as a colorless
−
1
oil. IR (neat oil) nmax / cm 2867-2947 (C-H aliphatic),
1
1701 (C=O), 1509-1599 (C=C); H NMR (400 MHz,
CDCl ) d 9.87 (s, 1H, CHO), 7.77 (d, 2H, J 8.6 Hz, 2 × CH),
3
6.97 (d, 2H, J 8.6 Hz, 2 × CH), 1.24-1.33 (m, 3H, J 7.4 Hz,
3 × CH), 1.11 (d, 18H, J 7.4 Hz, 6 × CH3).
0
1
3
.80 g (90% yield) of a light green product; mp obtained:
61
−1
15-116 °C (mp lit.: 115-117 °C); IR (KBr) n / cm
4-[(Triisopropylsilyl)oxy]phenylmethylenepyren-1-amine (2)
Compounds 1 (0.250 g, 1.15 mmol) and 7 (0.221 g,
1.15 mmol) were dissolved in dry ethanol (3 mL) containing
acetic acid (three drops) in a 50 mL round-bottomed
flask, which was closed and its content was stirred at
room temperature for 3 h. A gold yellow precipitate was
observed after the stirring time and dry ethanol (10 mL)
was then added. The solid was collected, recrystallized from
ethanol/methanol mixture (1:1; v/v) and, after filtration,
and washing with cold methanol, 0.330 g (60% yield)
of the product were obtained (mp 84-86 °C). IR (KBr)
max
345-3387 (N-H), 3036 (C-H aromatic), 1623-1512
1
(
C=C); H NMR (400 MHz, DMSO-d ) d 8.24 (d, 1H,
6
J 9.4 Hz, CH), 7.97 (d, 2H, J 7.8 Hz, 2 × CH), 7.94 (d,
1
1
H, J 7.8 Hz, CH), 7.89 (d, 1H, J 9.0 Hz, CH), 7.86 (d,
H, J 8.6 Hz, CH), 7.85 (t, 1H, J 7.6 Hz, CH), 7.69 (d, 1H,
J 8.6 Hz, CH), 7.34 (d, 1H, J 8.2 Hz, CH), 6.33 (s, 2H, NH2).
4
-(Pyren-1-ylimino)methylphenol (1a)
1
-Aminopyrene (0.200 g, 0.92 mmol) and
4
-hydroxybenzaldehyde (0.169 g, 1.38 mmol) were
−
1
dissolved in 5 mL of dry ethanol in a 10 mL beaker and
acetic acid (one drop) was added. The mixture was stirred
at room temperature for 4 h.A precipitate was formed after
the stirring time, the product was recrystallized and the
crystals collected were washed twice, using an ethanol/
acetone mixture (1:1; v/v) as the solvent, giving 0.150 g
nmax / cm 3041 (C-H aromatic), 2866-2943 (C-H
aliphatic), 1599 (C=N), 1509 (C=C), 1270 (C-H imine);
1
H NMR (400 MHz, C D O) d 8.81 (s, 1H, CH=N) 8.73
3
6
(d, 1H, J 9.4 Hz, CH), 8.29 (d, 1H, J 8.2 Hz, CH), 8.26
(d, 1H, J 7.8 Hz, CH), 8.25 (d, 1H, J 7.4 Hz, CH), 8.18
(d, 1H, J 9.4 Hz, CH), 8.15 (d, 1H, J 9.0 Hz, CH), 8.13 (d,
1H, J 9.0 Hz, CH), 8.12 (d, 1H, J 9.0 Hz, CH), 8.10 (d, 1H,
J 9.4 Hz, CH), 8.05 (t, 1H, J 7.4, 7.8 Hz, CH), 7.89 (d, 1H,
J 8.2 Hz, CH), 7.14 (d, 2H, J 8.6 Hz, 2 × CH), 1.33-1.42
(
51% yield) of a green product, with mp 229-232 °C.
−
1
IR (KBr) n / cm 3441 (O-H), 1605 (C=N), 1515-1577
max
1
(
C=C); H NMR (400 MHz, DMSO-d ) d 10.2 (s, 1H,
6