Supramolecular Chemistry
489
EtOAc/CH2Cl2 ! 50% EtOAc/CH2Cl2, the product was
obtained as a white solid (0.06 g, 0.24 mmol, 24% yield).
M.p. 217–2188C; 1H NMR dH (400 MHz, DMSO-d6):
10.9 (1H, s, ArZNHZCOZPyr), 10.2 (1H, s, ArZNHZ
COZMe), 8.34 (1H, d, J ¼ 8.4 Hz, ArZH), 8.11 (1H, d,
J ¼ 8.0 Hz, ArZH), 8.03 (1H, t, J ¼ 8.0 ArZH), 7.86 (1H,
d, J ¼ 7.6 Hz, ArZH), 7.77 (1H, t, J ¼ 8.0 Hz, ArZH),
7.05 (1H, d, J ¼ 7.2 Hz, ArZH), 2.43 (3 H, s, ArZCH3),
2.16 (3 H, s, CH3ZCO); 13C NMR dC (100 MHz, DMSO-
d6): 170.0, 161.6, 157.0, 151.0, 150.0, 146.8, 140.3, 139.0,
119.5, 117.2, 116.9, 110.0, 24.0, 23.6; accurate MS (m/z)
calculated: 293.1008 (M þ Na)þ, found: 293.1014; IR
nmax (cm21): 3355 (NH), 3251 (NH), 1689 (CvO), 1668
(CvO), 1447 (pyridine).
flash column chromatography (4% EtOAc/CH2Cl2),
resulting in the product obtained as a white solid (0.24 g,
0.64 mmol, 27%). M.p. 153.2–154.08C; 1H NMR dH
(400 MHz, DMSO-d6): 10.1 (1H, s, NH), 9.98 (1H, s, NH),
8.42 (1H, dd, J ¼ 6.8; 2.4 Hz, ArZH), 8.33–8.30 (2H, m,
2 £ ArZH), 7.92 (1H, dd, J ¼ 8.0; 2.0 Hz, ArZH), 7.83
(1H, t, J ¼ 7.8 Hz, ArZH), 7.63 (1H, dd, J ¼ 8.0; 0.8 Hz,
ArZH), 3.37 (3H, s, CH3), 1.48 (9H, s, (CH3)3); 13C NMR
dC (100 MHz, DMSO-d6): 178.3, 164.6, 153.1, 152.0,
149.2, 141.1, 128.7, 126.0, 109.0, 107.4, 80.1, 68.8, 53.4,
28.5, 27.9, 22.2; IR nmax (cm21): 3344 (NH2), 1693
(CvO).
Acknowledgements
We thank Trinity College Dublin, CSCB, SFI and IRCSET for
financial support. We also thank Dr John E. O’Brien for his help,
Dr Tony McElligot for his initial help and support and Dr Emma
B. Veale for helping out with the analysis of DNA denaturation
studies.
6-Acetamido-N-(6-methylpyridin-2-yl)nicotinamide (4)
Compound 9 (0.18 g, 1.0 mmol), 2-amino-5-picoline
(0.15 g, 1.0 mmol) and HOBt (0.15 g, 1.1 mmol) were
weighed out and dried under reduced pressure before
being dissolved in dry THF (10 ml) and cooled in an ice
bath for 30 min. EDCI HCl (0.21 g, 1.1 mmol) was added
and stirred for further 30 min at 08C and then stirred
overnight at room temperature. The solvent was removed
and the solid was dried under reduced pressure before
CH2Cl2 was added. The mixture was washed three times
with saturated NaHCO3 and the organic layer was dried
over MgSO4, filtered and evaporated to give white crystals
(0.04 g, 0.16 mmol, 16% yield). M.p. 216–2178C; 1H
NMR dH (400 MHz, DMSO-d6): 10.84 (1H, s, COZNHZ
Pyr), 10.83 (1H, s, COZNHZMe), 8.93 (1H, d,
J ¼ 2.4 Hz, ArZH), 8.37 (1H, dd, J ¼ 8.8; 2.8 Hz,
ArZH), 8.22 (1H, s, ArZH), 8.16 (1H, d, J ¼ 8.8 Hz,
ArZH), 8.08 (1H, d, J ¼ 8.4 Hz, ArZH), 7.67 (1H, dd,
J ¼ 8.4; 2.0 Hz, ArZH), 2.29 (3H, s, ArZCH3), 2.14 (3H,
s, CH3ZCO); 13C NMR dC (100 MHz, DMSO-d6): d
169.8, 163.9, 154.2, 149.9, 148.3, 147.7, 138.5, 138.1,
128.9, 125.0, 114.3, 112.0, 24.1, 17.4; accurate MS (m/z)
calculated: 293.1008 (M þ Na)þ, found: 293.1014; IR
nmax (cm21): 3355 (NH), 3251 (NH), 1689 (CvO), 1668
(CvO), 1449 (pyridine).
Note
1. The data for crystal 2 (CDC 743207) was collected on a
Rigaku Saturn 724 CCD Diffractometer. A suitable crystal
was mounted using inert oil on a 0.30 mm quartz fibre tip and
immediately placed on the goniometer head in a 121K N2 gas
stream. The data set was collected using Crystalclear-SM
1.4.0 software and 1926 diffraction images, of 0.58 per
image, were recorded. Data integration and reduction were
performed using Crystalclear-SM 1.4.0 software. The data
for crystal 5 (CCDC 743208) was collected on a Bruker
Smart Apex Diffractometer. A suitable crystal was mounted
using inert oil on a glass fibre tip and immediately placed on
the goniometer head in a 121K N2 gas stream. The data was
collected using Bruker Smart Version 5.625 software run in
multirun mode and 2400 image frames, of 0.38 per frame,
were recorded. Data integration and reduction were carried
out using Bruker Saint þ Version 6.45 software and
corrected for absorption and polarisation effects using
Sadabs Version 2.10 software.
References
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Methyl 6-(6-(tert-butoxycarbonylamino)pyridin-2-
ylcarbamoyl)-picolinate (5)
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Stirred solution of 19 (0.50 g, 2.4 mmol), 20 (0.50 g,
2.8 mmol) and HOBt (0.38 g, 2.8 mmol) was suspended in
THF. Triethylamine (0.5 ml, 2.6 mmol) and DCC (0.55 g,
2.4 mmol) were added to this solution at 48C and under
argon. This reaction mixture was stirred at 48C for 15 min
and then overnight at room temperature. The reaction
mixture was filtered and the solvent was removed under
reduced pressure. The reaction mixture was dried and then
suspended in CH2Cl2. The residue was separated by silica