Reference

Process for the preparation of 2-hydroxy-3-halogen-5-nitropyridines

Process for the preparation of 2-hydroxy-3-halogen-5-nitropyridines. Worsch, Detlev (Lonza A.-G., Switz.). Eur. Pat.Some commonly used reagents like 54127-63-8 and 22353-38-4 are used in this experiment. Appl. EP 467308 A2 22 Jan 1992, 3 pp. DESIGNATED STATES: R: AT, BE, CH, DE, DK, ES, FR, GB, IT, LI, NL, SE. (European Patent Organization). CODEN: EPXXDW. CLASS: ICM: C07D213-64. APPLICATION: EP 91-111871 16 Jul 1991. PRIORITY: CH 90-2373 17 Jul 1990. DOCUMENT TYPE: Patent CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) A process for the prepn. of 3-halo-2-hydroxy-5-nitropyridines comprises the nitration of 5-halo-6-hydroxynicotinic acid with HNO3/H2SO4. The 3-halo-2-hydroxy-5-nitropyridines are intermediates for pharmaceuticals and herbicides (no data). A mixt. of 70% HNO3 (200 mL), conc. H2SO4 (200 mL) and 5-chloro-6-hydroxy-3-pyridinecarboxylic acid (100 g) was heated to 50° for 2 h to give 3-chloro-2-hydroxy-5-nitropyridine (74% yield). .