Month 2019
Synthesis and Characterization of 2-(2-Pyridinyl)pyrazine and 2,20-Bipyrazine
Derivatives
J = 1.2 Hz, 1H); 13C-NMR (300 MHz, CDCl3) δ ppm 21.9,
142.2, 142.4, 143.1, 143.3, 143.5, 143.5, 143.9, 144.6,
145.0, 146.4, 149.6, 154.7. HRMS (ESI) m/z: [M + H]+
Calcd for C9H8N4 172.07; found 173.00. Anal. Calcd for
C9H8N4: C, 62.78, H, 4.68, N, 32.54. Found. C, 62.60,
necessary to maintain the temperature between 70°C and
80°C). Heating was discontinued after all the potassium
dichromate was added. The resulting deep green mixture
was poured into 500 mL of ice water. After the
temperature fell below 40°C, a light-green colored
precipitate was collected, washed with water until the
filtrate was white, and allowed to dry. The resulting white
solid was further purified by refluxing it in 60 mL of
50% nitric acid for 4 h. This solution was poured over
ice in 1 L of water. The solid 17 was removed by
filtration, washed with water (40–50 mL) and then with
acetone, (3 × 15 mL) and allowed to dry.
H, 4.46, N, 32.41.
2-Methyl-5-(2-pyridinyl)pyrazine (15). A modification of
the procedure described for the preparation of 6 (see
previous texts) was followed. 2-(Tributylstannyl)-5-
methylpyrazine (3.12 g, 8.16 mmol) in 60 mL of xylene
was reacted with 2-bromopyridine (1.28 g, 8.16 mmol) in
the presence of Pd (PPh3)4 (0.40 g, 0.36 mmol). The
crude solid product was purified via flash column
chromatography (silica gel, 230–450 mesh). First, the
impurities were removed by eluting with n-hexane/ethyl
acetate (3:1). Then, the desired compound was obtained
after eluting with n-hexane/ethyl acetate (1:3). Finally,
the eluting solvent was removed by rotary evaporation to
obtain 15 as a white color crystalline powder (0.93 g).
Color: White, Yield: 84%. 1H-NMR (400 MHz,
DMSO): δ ppm 9.34 (d, J = 1.2 Hz, 2H), 9.65 (d,
J = 2.4 Hz, 2H); 13C-NMR (300 MHz, DMSO) δ ppm
139.2, 145.4, 158.9, 162.2, 180.6. HRMS (ESI) m/z:
[M + H]+ Calcd for C10H6N4O4 246.03; found 247.00.
Anal. Calcd for C10H6N4O4·1½H2O: C, 43.92, H, 3.29,
N, 20.50. Found. C, 44.29, H, 3.80, N, 20.30.
1
Color: White, Yield: 64%. mp, 73°C H-NMR (CDCl3,
400 MHz): δ ppm 2.66 (s, 3H), 8.22 (d, J = 7.6 Hz, 1H),
7.71 (dd, J = 1.8, 1.2 Hz, 1H), 8.22 (d, J = 1.8 Hz, 1H),
8.38 (dd, J = 2.4, 1.2 Hz, 1H), 8.60 (dd, J = 2.4, 1.6 Hz,
1H), 9.41 (dd, J = 2.4, 1.2 Hz, 1H); 13C-NMR
(300 MHz, CDCl3) δ ppm 21.3, 120.9, 123.9, 136.8,
142.0, 143.1, 148.1, 143.9, 153.5. HRMS (ESI) m/z:
[M + H]+ Calcd for C10H9N3 171.07; found 172.00.;
Acknowledgments. We would like to acknowledge the funding
sources that we are grateful for support from the National
Science Foundation (EPSCOR), the Wichita State University
Office of Research, and the Department of Energy. We thank
Professor David Eichhorn and Dr. Curtis Moore for the X-ray
crystal structure determination and Matthew Baird for providing
the mass spectral data.
Anal. Calcd for C10H9N3: C, 70.16, H, 5.30, N, 24.54.
Found. C, 70.49, H, 5.36, N, 24.71.
5,50-Dimethyl-2,20-bipyrazine (16). A modification of the
procedure described for the preparation of 6 (see previous
REFERENCES AND NOTES
[1] Montgomery, T. D.; Rawal, V. H. Org Lett 2016, 18, 740.
[2] Dolezal, M.; Zitko, J. Expert Opin Ther Pat 2015, 25, 33.
[3] Schultz, D. M.; Sawicki, J. W.; Yoon, T. P. Beilstein J Org
Chem 2015, 11, 61.
[4] Wallace, L.; Rillema, D. P. Inorg Chem 1993, 32, 3836.
[5] Sahai, R.; Rillema, D. P.; Shaver, R.; Van Wallendael, S.;
Jackman, D. C.; Boldaji, M. Inorg Chem 1989, 28, 1022.
[6] Stoyanov, S. R.; Villegas, J. M.; Cruz, A. J.; Lockyear, L. L.;
Reibenspies, J. H.; Rillema, D. P. J Chem Theory Comput 2005, 1, 95.
[7] De La Torre, G.; Bottari, G.; Sekita, M.; Hausmann, A.; Guldi,
D. M.; Torres, T. Chem Soc Rev 2013, 42, 8049.
texts) was followed. 2-(Tributylstannyl)-5-methylpyrazine
(1.75 g, 4.73 mmol) in 40 mL of xylene was reacted with
2-bromo-5-methylpyrazine (0.78 g, 4.56 mmol) in the
presence of Pd (PPh3)4 (0.24 g, 0.21 mmol). The solid
was removed under rotary evaporation, and then, the
crude solid product was purified via flash column
chromatography (silica gel, 230–450 mesh) using n-
hexane/ethyl acetate (5:1) as eluent. Final, the eluting
solvent was removed by rotary evaporator to obtain 16 as
a white color crystalline powder (0.58 g).
[8] Salpage, S. R.; Paul, A.; Som, B.; Banerjee, T.; Hanson, K.;
Smith, M. D.; Vannucci, A. K.; Shimizu, L. S. Dalton Trans 2016, 45, 9601.
[9] Shaffer, D. W.; Xie, Y.; Szalda, D. J.; Concepcion, J. J. J Am
Chem Soc 2017, 139, 15347.
1
Color: White, Yield: 68%. mp, 148°C, Anal. H-NMR
(400 MHz, CDCl3): δ ppm 2.65 (s, 6H), 8.51 (d,
J = 2.0 Hz, 2H), 9.41 (d, J = 1.2 Hz, 2H); 13C-NMR
(300 MHz, CDCl3) δ ppm 21.52, 142.0, 143.4, 146.7,
154.1.17. HRMS (ESI) m/z: [M + H]+ Calcd for
C10H10N4 186.09; 187.00. Calcd for C10H10N4: C, 64.50,
H, 5.41, N, 30.09. Found. C, 64.76, H 5.49, N, 30.00.
[10] Wang, P.; Zakeeruddin, S. M.; Moser, J. E.; Nazeeruddin, M.
K.; Sekiguchi, T.; Grätzel, M. Nat Mater 2003, 2, 402.
[11] Zhang, Z.; Xu, J.; Yan, S.; Chen, Y.; Wang, Y.; Chen, Z.; Ni,
C. Crystals 2017, 7, 92.
[12] Grätzel, M. Inorg Chem 2005, 44, 6841.
[13] Ferrere, S.; Gregg, B. A. J Am Chem Soc 1998, 120, 843.
[14] Karmas, G.; Spoerri, P. E. J Am Chem Soc 1956, 78, 2141.
[15] Albinsson, B.; Eng, M. P.; Pettersson, K.; Winters, M. U. Phys
Chem Chem Phys 2007, 9, 5847.
[2,20-Bipyrazine]-5,50-dicarboxylic acid (17).
Potassium
dichromate (3.4 g, 3.8 mmol) was added in small
portions to a stirring solution of 5,50-dimethyl-2,20-
bipyrazine (0.72 g, 3.88 mmol) in sulfuric acid (60 mL,
98%) initially at 70°C. (Occasional cooling with a water
bath during the addition of potassium dichromate was
[16] Shih, C.; Museth, A. K.; Abrahamsson, M.; Blanco-Rodriguez,
A. M.; Di Bilio, A. J.; Sudhamsu, J.; Crane, B. R.; Ronayne, K. L.;
Towrie, M.; Jr, A. V.; Richards, J. H.; Winkler, J. R.; Gray, H. B. Science
2008, 320, 1730.
[17] Bronner, C.; Wenger, O. S. Phys Chem Chem Phys 2014, 16,
3617.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet