J.-E. Bäckvall et al.
FULL PAPER
quenched with pyridine (0.32 mL, 3.93 mmol). The mixture was
concentrated in vacuo below 30 °C to afford a yellow oil (if the
product precipitates it should be redissolved by the addition of a
minimal amount of ethanol). Chloroform was then added resulting
in the formation of pale yellow crystals. The mixture was filtered,
and the filter cake was washed with chloroform, and dried in vacuo
1649, 1596, 1563, 1521, 1475, 1389, 1374, 1355, 1316, 1254, 1134,
1091, 899, 848 cm–1. MS (ESI-TOF): calcd. for C33H29CoN3O6
+
[oxidized bis(benzoquinone) form] 622.1388; found 622.1354.
Supporting Information (see footnote on the first page of this arti-
cle): General methods and 1H and 13C NMR spectra of compounds
3 and 6.
1
at room temp. to give 7 (4.43 g, 98%). H NMR (400 MHz, [D6]-
DMSO): δ = 10.72 (br. s, 1 H, CHO), 10.29 (s, 1 H, OH), 8.24 (br.
s, 1 H, Ar-OH), 8.77 (br. s, 1 H, Ar-OH), 7.82 (d, J = 2 Hz, 1 H,
Ar-H), 7.70 (dd, J = 8, J = 2 Hz, 1 H, Ar-H), 7.02 (d, J = 8 Hz, 1
H, Ar-H), 6.73 (d, J = 8 Hz, 1 H, Ar-H), 6.65 (d, J = 2 Hz, 1 H,
Ar-H), 6.56 (dd, J = 8, J = 2 Hz, 1 H, Ar-H) ppm. 13C NMR
(100 MHz, [D6]DMSO): δ = 191.8, 159.5, 150.2, 146.7, 137.1,
130.0, 129.3, 126.7, 121.8, 116.8, 116.8, 115.9, 114.9 ppm. IR (KBr
Acknowledgments
We thank the Swedish Research Council and the K & A Wallenberg
Foundation for financial support.
disc): ν = 3375 (br.), 1653, 1639, 1501, 1489, 1458, 1323, 1278,
˜
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1202, 1176, 892, 873, 807, 783, 743, 725, 712, 624, 610 cm–1. MS
–
(ESI-TOF): calcd. for C13H9O4 229.0506; found 229.0504.
Bis{3-[5-(2,5-dihydroxyphenyl)salicylidenimino]propyl}methylamine
(9): Compound 7 (0.918 g, 3.98 mmol) was placed in a round-bot-
tomed flask and N-(3-aminopropyl)-N-methylpropane-1,3-diamine
(8, 0.269 g, 1.85 mmol) was added as a solution in ethanol (20 mL).
The reaction mixture was stirred at room temp. for 14 h. The sol-
vent was then removed by rotary evaporation. The crude product
could be used without further purification (0.959 g, 91% yield). 1H
NMR (400 MHz, [D6]DMSO): δ = 13.65 (br., s, 2 H, Ar-OH), 8.74
(br., s, 4 H, Ar-OH), 8.59 (s, 2 H, CHN), 7.57 (d, J = 2 Hz, 2 H,
Ar-H), 7.47 (dd, J = 8, J = 2 Hz, 2 H, Ar-H), 6.87 (d, J = 8 Hz, 2
H, Ar-H), 6.71 (d, J = 8 Hz, 2 H, Ar-H), 6.64 (d, J = 2 Hz, 2 H,
Ar-H), 6.53 (dd, J = 8, J = 2 Hz, 2 H, Ar-H), 3.63 (t, J = 6 Hz, 4
H, CH2), 2.40 (t, J = 6 Hz, 4 H, CH2), 1.79 (t, J = 6 Hz, 4 H, CH2)
ppm. 13C NMR (100 MHz, [D6]DMSO): δ = 166.1, 159.8, 150.1,
146.6, 133.0, 131.8, 128.9, 127.4, 118.0, 116.7, 116.1, 116.1, 114.5,
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Received: March 23, 2009
+
56.2, 54.6, 41.9, 28.2 ppm. MS (ESI-TOF): calcd. for C33H36N3O6
570.2599; found 570.2610.
(Bis{3-[5-(2,5-dihydroxyphenyl)salicylideniminato]propyl}methyl-
amine)cobalt(II) (A): Compound 9 and cobalt(II) acetate tetrahy-
drate (0.533 g, 2.14 mmol) were placed in a round-bottomed flask,
and dry methanol (20 mL) was added. The reaction mixture was
degassed by briefly evacuating the flask and back-filling with ar-
gon. The reaction mixture was then heated at 62 °C for 1 h and
cooled to room temp. The color had changed from orange to dark
brown. A colour change to purple was observed when the product
was exposed to air. The solvent was evaporated, and the crude
product was dried in vacuo overnight. The resulting solid was sus-
pended in water (10 mL), and the product was collected by fil-
tration. The filter cake was washed with water to give complex A
(1.02 g, 97%). IR (KBr disc): ν = 3431 (br.), 3043, 2927, 2858,
Published Online: June 30, 2009
˜
3976
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Eur. J. Org. Chem. 2009, 3973–3976