Molecules 2006, 11
133
Methyl 3-fluoropyridine-4-carboxylate (2).
Methyl 3-nitropyridine-4-carboxylate (1, 120 mg, 0,681 mmol) and CsF (517 mg, 3,406 mmol, 5
equivalents) was added to dry DMSO (6 mL) under N . The reaction mixture was heated at 120 °C for
2
9
0 minutes. TLC (4:1 EtOAc/pentane) showed complete conversion to the fluoro substituted product.
Distilled water (20 mL) was added to the reaction mixture, which was then extracted with EtOAc
3x20 mL) and concentrated in vacuo. The crude product was purified by flash chromatography (4:1
(
1
13
1
EtOAc/pentane) yielding 40 mg ( 38 %) of an oily product, pure by H- and C-NMR. H-NMR (400
4
MHz, CDCl ): δ 3.98 (d, J 2.0, 3H, OCH ), 7.77 (ddd, J 0.4, 4.8, J 6.0, 1H, H-5), 8.55 (dd, J 0.8,
3
HF
3
HF
3
13
3
4
.8, 1H, H-6), 8.62 (d, JHF 2.4, 1H, H-6); C-NMR (100 MHz, CDCl
3
): δ 53.0 (s), 124.4 (d, JCF 1.5
2
3
1
C5), 125.2 (d, JCF 8.0, C4), 140.4 (d, JCF 25.3, C2), 157.1 (d, JCF 268.0, C3), 163.3 (d, JCF 3.0,
1
9
C=O); F-NMR (376 MHz, C D ): δ -125.5 (dd, J 2.3, 6.0, F3); IR (film) υmax: 3020w, 2926m,
6
6
HF
-1
+
1
744s, 1538m, 1438w, 1352m, 1277m, 758s cm ; MS: m/z 155 (M , 24%), 149 (11), 124 (43), 111
(
13), 109 (13), 96 (23); Anal. Calcd. for C H FNO : C, 54.20; H, 3.90; N, 9.03. Found: C, 53.96; H,
7
6
2
3
.68; N, 8.86.
References
1
2
3
.
.
.
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Chambers, R. D. Fluorine in Organic Chemistry; Oxford: Blackwell, 2004.
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nitrobiphenyls and nitronaphthalenes. Chem. Ber. 1991, 124, 163-173.
4
5
. Beck, J. R. Nucleophilic displacement of aromatic nitro groups. Tetrahedron 1978, 34, 2057-2068.
.
Kuduk, S. D.; DiPardo, R. M.; Bock, M. G. Tetrabutylammonium Salt Induced Denitration of
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Holt, J.; Tjosås, F.; Bakke, J.; Fiksdahl, A. Nucleophilic aromatic substitution of methyl 3-
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Sample Availability: Available from the authors.
2006 by MDPI (http://www.mdpi.org). Reproduction is permitted for noncommercial purposes.
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