The Journal of Organic Chemistry
Article
−
=
248 g/mol, [M] = 230.0 g/mol. HRMS (MALDI; solvent, CH Cl ;
133.8, 130.5, 130.1, 129.7, 128.0, 127.0, 117.1, 116.4, 114.7, 114.6,
114.1, 56.6, 28.3. LRMS MALDI (solvent, CH Cl ; matrix, DCTB)
2
2
+
matrix, DCTB): C H N O [M + H]
= 231.0543 g/mol, [M +
1
5
7
2
measured
2
2
+
+
H]
= 231.0558 g/mol. mp 294−300 °C. Anal. Calcd: C, 78.26;
[M + Na] = 455.1 g/mol. HRMS MALDI (CH Cl , Matrix DCTB,
calculated
2 2
+
H, 2.63; N, 12.17. Found: C, 78.23; H, 2.83; N, 12.15. Solubility in
common solvents: soluble in DMSO and boiling acetonitrile, slightly
soluble in cold acetonitrile, dichloromethane, and chloroform,
sparingly soluble in toluene, and insoluble in alkanes and cyclohexane.
Synthesis of 1-Oxo-1H-phenalene-2,3-dicarbonitrile (5) in a
One-Pot Sequence. To a suspension of malononitrile (72 mg, 1
equiv, 1.09 mmol) in acetonitrile (4 mL) were added successively
Standard: PEG200): C H N OSNa [M + Na]
= 354.0665 g/
measured
1
9
13
3
+
mol, [M + Na]
= 354.0671 g/mol. Single crystal preparation:
calculated
Crystals (dark-violet needles) were prepared by diffusion of liquid
cyclohexane through a saturated solution of 2 in dichloromethane.
UV−visible (solvent: dichloromethane): λ
= 575 nm, λmax2 = 540
max1
em
nm, λ
= 306 nm. Fluorescence: λ
= 606 nm. Φ = 0.03
max3
max
f
(standard: Rhodamine B in 2 mL of MeOH + 1 drop of TFA, Φ =
f
2
acenaphtylene-1,2-dione 3 (200 mg, 1 equiv, 1.09 mmol) and K CO3
14 mg, 0.1 equiv, 0.10 mmol). After 1 h of reflux, the solvent was
removed under reduced pressure, and the crude was purified on silica
gel (CH Cl 100%). The expected product 5 was isolated as bright
orange flakes (151 mg, yield = 60%). See above for characterization
data.
Mechanistic Elucidation by Isotopic Assignment of 1-Oxo-
H-phenalene-2,3-dicarbonitrile (11). 1-Oxo-1H-phenalene-2,3-
dicarbonitrile 11 from compound 5 was synthesized as follows: To a
suspension of 1-oxo-1H-phenalene-2,3-dicarbonitrile 5 (150 mg, 1.0
equiv, 0.65 mmol) in acetonitrile (5 mL) were successively added
K CO (9 mg, 0.1 equiv, 0.065 mmol) and K CN (21 mg, 0.5 equiv,
.325 mmol). After 1.5 h of reflux, the solvent was removed under
reduced pressure, and the crude was purified on silica gel (eluent:
CH Cl 100%). The expected product 11 was isolated as bright orange
flakes (45 mg, yield = 31%).
-Oxo-1H-phenalene-2,3-dicarbonitrile 11 from compound 3 was
synthesized as follows: To a suspension of malononitrile (54.4 mg, 1
equiv, 0.824 mmol) in acetonitrile (5 mL) were added successively
acenaphtylene-1,2-dione 3 (150 mg, 1.0 equiv, 0.824 mmol), K CO
0.40). Note that sonication or trituration of the crude in dichloro-
methane followed by filtration may remove most of the unreacted
compound 5 (slightly soluble in dichloromethane). Dry loading on
silica gel must be avoided because lower yields were obtained. A
(
2
2
solution of compound 2 in CDCl showed significant decomposition
3
(TLC analysis 10 min after solubilization; analysis of the solution after
room temperature overnight storage showed that compound 2 was the
minor species in the NMR tube). Compound 2 is soluble in
dichloromethane, hot chloroform, acetonitrile, and DMSO, slightly
soluble in cold chloroform, acetone, and toluene, sparingly soluble in
diethyl ether and a dichloromethane 50%/diethyl ether 50% mixture,
and insoluble in alkanes and cyclohexane.
1
13
2
3
0
6
-(n-Butylamino)-1-oxo-1H-phenalene-2,3-dicarbonitrile
(
(
12), 9-(Butylamino)-1-oxo-1H-phenalene-2,3-dicarbonitrile
13), and 3-(n-Butylamino)-1-oxo-1H-phenalene-2,3-dicarboni-
2
2
trile (14). To a suspension of 1-oxo-1H-phenalene-2,3-dicarbonitrile 5
1
(500 mg, 1 equiv, 2.17 mmol) in acetonitrile (90 mL) was added n-
butylamine (1.07 mL, 792 mg, 4 equiv, 10.8 mmol), and the reaction
mixture was stirred for 3 h at room temperature. A few minutes after
adding n-butylamine, the reaction mixture became deep blue. The
solvent was removed under reduced pressure, and the resulting black
solid was purified by silica gel column chromatography (from CH Cl
2
3
13
(
10 mg, 0.1 equiv, 0.082 mmol), and K CN (27 mg, 0.5 equiv, 0.412
mmol). After refluxing the suspension over 1.5 h, the solvent was
removed under reduced pressure, and the crude was purified on silica
gel (eluent: CH Cl 100%). The expected product 11 was isolated as
bright orange flakes (28 mg, yield = 15%).
-Oxo-1H-phenalene-2,3-dicarbonitrile 11 from compound 4 was
synthesized as follows: To a suspension of 2-(2-oxo-2H-acenaph-
thylene-1-ylidene)-malononitrile 4 (128 mg, 1.0 equiv, 0.56 mmol) in
acetonitrile (4 mL) were added K CO (7.7 mg, 0,1 equiv, 0.056
mmol), and K CN (18,5 mg, 0.5 equiv, 0.28 mmol). After refluxing
the suspension for 1.5 h, the solvent was removed under reduced
pressure, and the crude was purified on silica gel (eluent: CH Cl2
00%). The expected product 11 was isolated as a bright orange flakes
2
2
1
00% to CH Cl2 95%/MeOH 5%). 6-(Butylamino)-1-oxo-1H-
2
2
2
phenalene-2,3-dicarbonitrile 12 was obtained as a dark purple powder
1
(
138 mg, yield = 21%). H NMR (CD Cl 93%/CD OD 7%, 500
2 2 3
1
MHz, 30 °C): δ 8.69 (dd, J = 1.1 Hz, J = 7.6 Hz, 1H), 8.67 (dd, J = 1.0
Hz, J = 8.1 Hz, 1H), 8.13 (d, J = 9.0 Hz, 1H), 7.82 (d, J = 7.9 Hz, J =
7
.9 Hz, 1H), 6.84 (d, J = 9.1 Hz, 1H), 3.57 (t, J = 7.4 Hz, 2H), 1.79
2
3
(
=
quintuplet, J = 7.4 Hz, 2H), 1.49 (sextuplet, J = 7.4 Hz, 2H), 1.00 (t, J
7.4 Hz, 4H). C NMR (CD Cl 93%/CD OD 7%, 125 MHz, 30
2 2 3
13
13
°
1
C): δ 178.7, 156.9, 140.0, 133.9, 131.99, 131.97, 129.5, 128.0, 127.7,
23.1, 116.2, 114.8, 113.3, 108.0, 106.7, 44.7, 31.1, 20.8, 14.0. HRMS:
2
1
(
+
= 302.1290 g/mol, [M + H]+
ESI, C H N O [M + H]
19
16
3
measured
calculated
30 mg, yield = 23%).
All NMR spectra of the enriched derivative 11 were recorded and
displayed the following data: H NMR (500.13 MHz, CD Cl ): δ
.77 (dd, J = 1.0, 7.5 Hz, 1H), 8.46 (dd, J = 0.9, 8.0 Hz, 1H), 8.42 (dd,
=
302.1293 g/mol. UV−visible spectroscopy (solvent: dichloro-
−1 −1
25
1
methane): λmax1 = 573 nm, ε (λmax1) = 47 717 L mol cm , λmax2
=
=
2
2
−1
−1
534 nm, ε (λmax2) = 19 491 L mol cm , λ
= 303 nm, ε (λmax3)
max3
8
−
1
−1
12 159 L mol cm . Fluorescence spectroscopy (solvent:
J = 0.8 Hz, 7.4 Hz, 1H), 8.39 (d, J = 8.2 Hz, 1H), 7.96 (dd, J = 7.7, 7.7
em
Hz, 1H), 7.86 (dd, J = 7.6, 8.0 Hz, 1H). 13C NMR (125.76 MHz,
CD Cl ): 178.1, 138.4, 138.1, 134.9, 133.8, 132.7, 132.3, 129.3, 128.4,
dichloromethane): λ max1 = 586 nm, Φ
f
= 0.60 (standard: Rhodamine
B in 2 mL of MeOH + 1 drop of TFA, Φ = 0.40). 9-(n-Butylamino)-
f
2
2
1
-oxo-1H-phenalene-2,3-dicarbonitrile 13 was also present in the
1
28.0, 127.4, 123.1, 120.6, 113.5, 113.4.
Synthesis of the Newly Assigned 1-Oxo-6-thiomorpholino-
H-phenalene-2,3-dicarbonitrile (2). Compound 2 was synthe-
reaction mixture but could not be separated from the starting material.
A pure analytic fraction could be separated for its characterization (65
1
1
5a
mg, 10%). H NMR (CD Cl , 400 MHz, 30 °C): δ 12.68 (broad
sized according to the procedure described by Liu et al. A mixture of
thiomorpholine (1.31 mL, 1.43 g, 4 equiv, 13.9 mmol) and 1-oxo-1H-
phenalene-2,3-dicarbonitrile 5 (800 mg, 1.0 equiv, 3.47 mmol) in
acetonitrile (140 mL) was stirred for 2 to 3 h at room temperature.
After mixing, the reaction mixture turned to a green color and then to
a purple color. After reaction completion, acetonitrile was removed
under reduced pressure, and the crude was purified by column
chromatography on silica gel (eluent: from CH Cl 100% to CH Cl
9.9%/acetone 0.1%). Compound 2 was obtained as a dark-purple
powder (596 mg, yield = 52%) and was recrystallized in chloroform. Rf
0.60 (CH Cl /acetone: 98/2). H NMR (DMSO-d , 400 MHz, 30
C, high dilution): δ 8.66 (m, 2H), 8.18 (d, J = 8.9 Hz, 1H), 7.96 (dd,
2
2
singlet, 1H), 8.35 (dd, J = 1.0, 7.9 Hz, 1H), 8.14 (dd, J = 1.0, 7.5 Hz,
1
9
H), 8.10 (d, J = 9.4 Hz, 1H), 7.64 (dd, J = 7.7 Hz, 1H), 7.32 (d, J =
1
3
.5 Hz, 1H), 3.68 (m, 2H), 1.86 (m, 2H), 1.03 (t, J = 7.3 Hz, 3H).
C
NMR (CD Cl , 100 MHz, 30 °C): δ 176.3, 158.5, 141.0, 136.6, 132.3,
2
2
129.4, 126.2, 125.4, 124.2, 121.2, 118.3, 116.2, 115.1, 114.5, 110.0,
43.9, 31.7, 20.8, 14.0. HRMS: ESI, C19H N =
O [M + H]+measured
16 3
+
302.1288 g/mol, [M + H] calculated = 302.1293 g/mol. 3-(n-
2
2
2
2
9
Butylamino)-1-oxo-1H-phenalene-2,3-dicarbonitrile 14 (18 mg, 3%)
1
was also isolated. H NMR (CDCl
, 400 MHz, 30 °C): δ 8.55 (dd, J =
3
1
=
°
1.3 Hz, J = 7.2 Hz, 1H), 8.18 (m, 2H), 7.99 (d, 7.5 Hz, 1H), 7.76 (dd,
J = 7.3 Hz, J = 8.0 Hz, 1H), 7.70 (dd, J = 7.8 Hz, J = 7.8 Hz, 1H), 4.06
2
2
6
1
3
J = 7.4 Hz, 1H), 7.42 (d, J = 8.4 Hz, 1H), 3.94 (m, 4H), 2.97 (m, 4H)
(m, 2H), 1.85 (m, 2H), 1.56 (m, 2H), 1.02 (t, J = 7.4 Hz, 3H). C
1
or H NMR (CD Cl , 400 MHz, 30 °C): δ 8.81 (dd, J = 1.2, 7.5 Hz,
NMR (CDCl , 100 MHz, 30 °C): δ 176.3, 158.5, 141.1, 136.6, 132.3,
2
2
3
1
H), 8.53 (dd, J = 1.0, 8.4 Hz, 1H), 8.24 (d, J = 8.4 Hz, 1H), 7.89 (d, J
8.0 Hz, 1H), 7.21 (d, J = 8.5 Hz, 1H), 3.81 (m, 4H), 2.98 (m, 4H).
129.4, 126.2, 125.4, 124.2, 121.2, 118.3, 116.2, 115.1, 114.5, 110.0,
+
=
43.9, 31.7, 20.8, 14.0. (ESI-QTOF) C H N O [M + H]
=
18
16
2
measured
1
3
+
C NMR (CD Cl , 100 MHz, 30 °C): δ 178.6, 161.4, 136.8, 134.3,
277.1331 g/mol, [M + H]
= 277.1335).
2
2
calculated
F
dx.doi.org/10.1021/jo5016932 | J. Org. Chem. XXXX, XXX, XXX−XXX