ChemicalBook CAS DataBase List 2-Chloro-5-nitropyridine

2-Chloro-5-nitropyridine synthesis

11synthesis methods

Product Name:2-Chloro-5-nitropyridine
CAS Number:4548-45-2
Molecular formula:C5H3ClN2O2
Molecular Weight:158.54

Into a 500 ml four-necked flask equipped with a thermometer, stirring and reflux condenser, 50 g of phosphorus oxychloride, 14.0 g (0.1 mole) of 2-hydroxy-5-nitropyridine prepared in Example 1, 25.0 g (0.12 Mol) Phosphorus pentachloride,Stir and react at 100-105°C for 5 hours,Then the phosphorus oxychloride was recovered by distillation under reduced pressure, and the remainder was slowly poured into 120 grams of ice water, fully stirred, and then a 40wt% aqueous sodium hydroxide solution was neutralized to a pH of 8-9.Separate the layers, extract the aqueous layer with dichloromethane three times, 60 grams each time, combine the organic phases,Washed with 20 grams of saturated brine, then dried with 2.0 grams of anhydrous sodium sulfate, distilled to recover dichloromethane, and dried to obtain 15.1 grams of 2-chloro-5-nitropyridine (I), yield 95.3%, gas purity 99.8 %.

2530-26-9
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4548-45-2
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$6.00/5g

Yield:4548-45-2 98%

Reaction Conditions:

with hypochlorous anhydride;triethylamine;zinc(II) chloride;dinitrogen monoxide in dichloromethane at -15 - 20; for 4 h;Green chemistry;Reagent/catalyst;Temperature;Solvent;

Steps:

1-4 Example 2

In the specific implementation of the present invention,A preparation method for preparing 2-chloro-5-nitropyridine by using nitrous oxideAdding 12.4-g of 3-nitropyridine to the reaction vessel,Triethylamine 20.2g,Zinc chloride 16g,Mix 200mL of dichloromethane evenly,Ice salt bath to -15 ° C; at 0 ° C take 17 g of dichlorous oxide,Soluble in 100mL of dichloromethane,Then, the nitrous oxide solution is slowly added to the above reaction solution.The reaction solution is maintained at -10 ° C to 0 ° C,After the addition is completed within 2 hours,Warm up to room temperature and continue to stir 2Hours to complete reaction of the raw materials,Pour the reaction solution into 300 mL of ice water.After stirring for half an hour,Divide the organic layer,Collect organic layers,The organic layer was washed once with 100 mL of a 5% strength hydrochloric acid.Wash once in 100mL water,Dry over anhydrous magnesium sulfate,After filtering,Evaporate the solvent under reduced pressure.154g of yellow 2-chloro-5-nitropyridine solid,Yield 98%,The normalized purity of liquid chromatography is greater than 99%.

References:

CN108689920,2018,A Location in patent:Paragraph 0014; 0017-0024