4-bromopyridine
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| General | ||||||||||||||||
| Surname | 4-bromopyridine | |||||||||||||||
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| Molecular formula | C 5 H 4 BrN | |||||||||||||||
| Brief description |
colorless liquid, white, non-hygroscopic solid as hydrochloride |
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| properties | ||||||||||||||||
| Molar mass | 158.00 g mol −1 | |||||||||||||||
| Physical state |
liquid |
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| Melting point |
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| boiling point |
30 ° C (53 Pa ) |
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| Dipole moment |
0.86 D |
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| Refractive index |
1.5694 (20 ° C) |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C | ||||||||||||||||
4-Bromopyridine is an organic compound that belongs to the heterocycles (more precisely: heteroaromatic compounds ). It consists of a pyridine ring which is substituted in the 4-position with bromine . The compound is isomeric to 2-bromopyridine and 3-bromopyridine .
presentation
4-bromopyridine can be used in very good yield by diazotization of 4-aminopyridine and subsequent substitution with bromine and hydrobromic acid are obtained.
use
2,4'-Bipyridine can be prepared from 2-bromopyridine and 4-bromopyridine by a Negishi coupling . For this purpose, 2-bromopyridine is first lithiated with n- butyllithium and transmetallated to zinc organyl with the addition of zinc chloride . A palladium complex with triphenylphosphine ligands is used as the coupling catalyst .
Individual evidence
- ↑ a b c A. Murray III, WH Langham: A Synthesis of Isonicotinic Acid by Halogen-Metal Exchange and Its Application to the Preparation of Isonicotinic-C 14 Acid Hydrazide , in: J. Am. Chem. Soc. , 1952 , 74 , pp. 6289-6290; doi : 10.1021 / ja01144a515 .
- ↑ a b c C. WN Cumper, AI Vogel: Physical properties and chemical constitution. Part XXX. The dipole moments of some halogeno- and cyano-pyridines , in: J. Chem. Soc. , 1960 , pp. 4723-4728; doi : 10.1039 / JR9600004723 .
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-70.
- ↑ a b Data sheet 4-bromopyridinium chloride (PDF) from Merck , accessed on September 6, 2012.
- ^ DR Sidler, N. Barta, W. Li, E. Hu, L. Matty, N. Ikemoto, JS Campbell, M. Chartrain, K. Gbewonyo, R. Boyd, EG Corley, RG Ball, RD Larsen, PJ Reider , Paul J: Efficient synthesis of the optically active dihydropyrimidinone of a potent α 1A -selective adrenoceptor antagonist. In: Canadian Journal of Chemistry . 80 (6), 2002, pp. 646-652, doi : 10.1139 / v02-079 .