2-CHLORO-5-FLUORO-3-NITROPYRIDINE synthesis

5synthesis methods

Product Name:2-CHLORO-5-FLUORO-3-NITROPYRIDINE
CAS Number:136888-21-6
Molecular formula:C5H2ClFN2O2
Molecular Weight:176.53

136888-20-5
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$8.00/100mg

136888-21-6
148 suppliers
$6.00/100mg

Yield:136888-21-6 70%

Reaction Conditions:

with benzyltrimethylammonium chloride;trichlorophosphate in acetonitrile at 80; for 6 h;

Steps:

4.a

a) Synthesis of 2-chloro-5-fluoro-3-nitro-pyridine 5-fluoro-3-nitro-pyridin-2-ol (2 g, 12.7 mmol) and benzyltrimethyl ammonium chloride (1.17 g, 6.35 mmol) were dissolved in acetonitrile, and phosphorus oxychloride (3.5 ml, 38.1 mmol) was added thereto and stirred at 80° C. for 6 hours. The reaction mixture was cooled and poured into ice water to quench the reaction, and extracted with dichloromethane. The combined organic layer was washed with saturated saline solution, dried over anhydrous sodium sulfate (Na₂SO₄), filtered and evaporated under reduced pressure. The residue was purified by column chromatography on silica eluding with a solvent of dichloromethane:methanol=30:1. The fractions containing the product were collected and evaporated to obtain yellow liquid (1.57 g, 70%). ¹H-NMR (CDCl₃, 300 MHz); δ=8.56 (d, J=2.7 Hz, 1H), 8.40 (dd, J=6.5 Hz, 2.7 Hz, 1H). MS (ESI); 176.9 (M⁺+1).

References:

US2011/28467,2011,A1 Location in patent:Page/Page column 52

884495-37-8 Synthesis