J Chem Crystallogr (2011) 41:192–197
193
N
N
N
N
N
N
N
N
Br
N
N
N
N
Br
S
S
Br
S
4
2
3
1
Scheme 1 Dipyridylamine derivatives 1–4 studied in this work
N-(4-bromophenyl)-N-(pyridin-2-yl)pyridin-2-amine
(1) [10, 19]
141.8, 137.5, 133.1, 127.7, 127.2, 126.3, 126.2, 120.1, 118.2,
117.0.
1,4-Dibromobenzene (0.6008 g,2.5 9 10-3 mol), 2,20-dipyr-
idylamine (0.2119 g, 1.2 9 0-3 mol), potassium phosphate
(0.9049 g, 4.2 9 10-3 mol) and CuI2 (0.0811 g, 4.3 9
10-4 mol) were thoroughly ground in a mortar, placed in a
100 ml round bottom flask under nitrogen atmosphere with
3.0 ml dry DMF and heated to 110 °C overnight. The
solvent was removed under reduced pressure upon cooling
and the crude product washed with ethyl acetate and fil-
tered. Purification by flash chromatography with hex-
anes:THF 2:1 as the eluent yielded the product in 70.6%
yield. X-ray quality crystals formed within a month upon
dissolving the compound in 1:1 ethanol/ethyl acetate.
1H-NMR (d, ppm, CDCl3, 400 MHz): 8.31 (2H, dd,
J = 4.5, 1.5 Hz), 7.55 (2H, tdd, J = 7.4, 4.9, 2.4 Hz), 7.45
(2H, d, J = 8.7 Hz), 7.04 (2H, d, J = 8.7 Hz), 6.99 (2H, d,
J = 8.3 Hz), 6.93 (2H, tdd, J = 6.4, 4.0, 1.3 Hz).
13C-NMR (d, ppm, CDCl3, 400 MHz): 157.7, 148.6, 144.0,
138.6, 137.6, 132.6, 128.3, 118.4, 117.0.
3-(3,5-dibromophenyl)thiophene (3) [20]
1,3,5-Tribromobenzene (0.2079 g, 6.604 9 10-4 mol), tribu-
tyltinthiophene (0.3000 g, 8.04 9 10-4 mol), Pd(PPh3)4
(0.0402 g, 3.5 9 10-6 mol) and DMF were placed in a flask
and heated to 110 °C overnight. Upon cooling, the DMF was
removed under reduced pressure and the product was puri-
fied by flash chromatography using hexanes:CHCl3 30:1 as
the eluent. Upon removal of the solvent under reduced
pressure, the product was isolated in 11.7% yield. 1H-NMR
(d, ppm, CDCl3, 400 MHz): 7.65, (2H, s), 7.58 (1H, s), 7.47
(1H, dd, J = 1.4, 3.0 Hz), 7.40 (1H, dd, 1.4, 5.1 Hz), 7.30
(1H, dd, J = 1.4, 5.0 Hz).
N1,N1,N3,N3-tetra(pyridin-2-yl)-5-(thiophen-3-yl)
benzene-1,3-diamine (4) [20]
3-(3,5-Dibromophenyl)thiophene (0.3424 g, 1.08 9 10-3
mol), 2,20-dipyridylamine (0.3154 g, 1.84 9 10-3 mol),
potassium carbonate (0.3974 g, 2.87 9 10-3 mol) and
copper(II) sulfate (0.1001 g, 6.27 9 10-4 mol) were
placed in a schlenk and heated to 210 °C for 8 h. Upon
cooling, the mixture was extracted with CH2Cl2 and
washed with water. The product was purified by flash
chromatography using THF:hexanes 1:1 as the eluent.
Upon removal of the solvent under reduced pressure, the
product was isolated in 23.0% yield. X-ray quality crystals
formed within 1 month upon dissolution of the compound
N-(pyridin-2-yl)-N-(4-(thiophen-3-yl)phenyl)pyridin-
2-amine (2) [20]
p-Bromo-dipyridylaminobenzene (0.5036 g, 1.54 9 10-3 mol),
tributyltinthiophene (0.75 g, 2.0 9 10-3 mol), Pd(PPh3)4
(0.0888 g, 7.7 9 10-6 mol) and 60 ml DMF were heated
overnight to 110 °C. Upon cooling to room temperature, the
solvent was removed under reduced pressure. Purification
through flash chromatography with 1:2 THF:hexanes as the
eluent, washing with 1% NaF and water yielded the product
in 33.9% yield. 1H-NMR (d, ppm, CDCl3, 400 MHz): 8.34
(2H, dd, J = 4.9, 1.2 Hz), 7.57 (3H, m), 7.41 (2H, t, J =
2.1 Hz), 7.36 (2H, d, J = 2.1 Hz), 7.20 (1H, d, J = 8.3 Hz),
7.03 (1H, d, J = 8.3 Hz), 6.93 (4H, dd, J = 7.1, 5.1 Hz).
13C-NMR (d, ppm, CDCl3, 400 MHz): 158.0, 148.6, 143.9,
1
in acetonitrile. H NMR (d, ppm, CDCl3, 400 MHz): 8.30
(4H, ddd, J = 4.9, 2.0, 0.8 Hz), 7.54 (4H, ddd, J = 8.3,
7.3, 2.0 Hz), 7.27 (2H, ddd, J = 7.9, 4.0, 2.2 Hz), 7.18
(1H, m), 7.07 (2H, dt, J = 8.3, 0.9 Hz), 6.91 (4H, ddd,
J = 7.3, 4.9, 1.0 Hz), 6.88 (1H, t, J = 2.0 Hz), 6.78 (4H,
d, J = 8.8 Hz). 13C-NMR (d, ppm, CDCl3, 400 MHz):
123