Pyrazine
From Wikipedia, the free encyclopedia
| Pyrazine | |
|---|---|
 |
|
| IUPAC name | Pyrazine |
| Other names | 1,4-Diazabenzene, p-Diazine, 1,4-Diazine, Paradiazine, Piazine, UN 1325 |
| Identifiers | |
| CAS number | [290-37-9] |
| PubChem | |
| EINECS number | |
| ChEBI | |
| SMILES | C1=CN=CC=N1 |
| InChI | 1/C4H4N2/c1-2-6-4-3-5-1/h1-4H |
| Properties | |
| Molecular formula | C4H4N2 |
| Molar mass | 80.09 g/mol |
| Appearance | White crystals |
| Density | 1.031 g/cm3 |
| Melting point |
52 ºC |
| Boiling point |
115 ºC |
| Solubility in water | Soluble |
| Hazards | |
| NFPA 704 |
 2
2
0
|
| R-phrases | R11, R36/37/38 |
| S-phrases | S16, S26, S36 |
| Flash point | 55 ºC c.c. |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Pyrazine is a heterocyclic aromatic organic compound.
Pyrazine is a symmetrical molecule with point group D2h. It is found in folic acid in the form of pterin. Derivatives like Phenazine are well known for their antitumor, antibiotic and diuretic activity. Pyrazine is less basic in nature than pyridine, pyridazine and pyrimidine. Tetramethylpyrazine is reported to scavenge superoxide anion and decrease nitric oxide production in human polymorphonuclear leukocytes[1]. It is also found on the cigarette additives list.
Contents |
[edit] Synthesis
Many methods exist for the organic synthesis of pyrazine and derivatives and some of them very old.
In the Staedel-Rugheimer pyrazine synthesis (1876) 2-chloroacetophenone is reacted with ammonia to the amino ketone, then condensed and then oxidized to a pyrazine [2] A variation is the Gutknecht Pyrazine Synthesis (1879) also based on this selfcondensation but differing in the way the alpha-ketoamine is synthesised (the chlorine compound in the above method is a lachrymatory agent) [3] [4]
The Gastaldi synthesis (1921) is another variation [5] [6]:
[edit] See also
- Pyrimidine, an analog with the second nitrogen atom in position 3.
- Pyridazine, an analog with the second nitrogen atom in position 2.
- Pyridine, an analog with only one nitrogen atom.
- Benzene, an analog without the nitrogen atoms.
- Simple aromatic rings
- Methoxypyrazines
[edit] External links
[edit] References
- ^ Life Sciences, 2003, 72, 2465-2472, DOI: http://dx.doi.org/10.1016/S0024-3205(03)00139-5
- ^ Ueber die Einwirkung von Ammoniak auf Chloracetylbenzol (p 563-564) W. Staedel, L. Rügheimer doi:10.1002/cber.187600901174 Berichte der deutschen chemischen Gesellschaft Volume 9, Issue 1 , Pages 563 - 564 1876
- ^ Mittheilungen Ueber Nitrosoäthylmethylketon H. Gutknecht Berichte der deutschen chemischen Gesellschaft Volume 12, Issue 2 , Pages 2290 - 2292 1879 doi:10.1002/cber.187901202284
- ^ Heterocyclic chemistry T.L. Gilchrist ISBN 0-582-01421-2
- ^ G. Gastaldi, Gazz. Chim. Ital. 51, (1921) 233
- ^ Amines: Synthesis, Properties and Applications Stephen A. Lawrence 2004 Cambridge University Press ISBN 0521782848
