ChemicalBook CAS DataBase List 4,6-DICHLORO-PYRIDIN-3-YLAMINE

4,6-DICHLORO-PYRIDIN-3-YLAMINE synthesis

8synthesis methods

Product Name:4,6-DICHLORO-PYRIDIN-3-YLAMINE
CAS Number:7321-93-9
Molecular formula:C5H4Cl2N2
Molecular Weight:163

70593-57-6

7321-93-9

The general procedure for the synthesis of 2,4-dichloro-5-aminopyridine from 4,6-dichloropyridin-3-amide was as follows: sodium hydroxide (6.60 g, 165 mmol) was dissolved in water (31 mL) and cooled in an ice bath. Subsequently, bromine (2.08 mL, 40.6 mmol) was added dropwise and the resulting yellow solution was stirred for 15 minutes. A 1,4-dioxane (21 mL) solution of 4,6-dichloronicotinamide (7.27 g, 38.1 mmol) was slowly added dropwise to the above bromine solution over 30 minutes. The reaction mixture was allowed to gradually warm up to 25°C over 18 hours. Upon completion of the reaction, the volatiles were removed by distillation under reduced pressure and the remaining solution was diluted with brine and poured into ethyl acetate. The aqueous phase was separated and extracted twice with ethyl acetate. The organic layers were combined, dried with sodium sulfate, decanted and concentrated to give an orange colored oil. The oily substance was purified by passing through a 100 g silica gel fast column using 25% ethyl acetate-hexane as eluent to give 4,6-dichloropyridin-3-ylamine as a brown solid (4.54 g, 73% yield). Finally, 30% aqueous hydrogen peroxide solution (29 mL) was cooled in an ice bath.

70593-57-6 Synthesis

70593-57-6
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$10.00/250mg

7321-93-9
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$20.00/100mg

Yield:7321-93-9 73%

Reaction Conditions:

with sodium hydroxide;water;bromine in 1,4-dioxane at 0 - 25; for 18 h;

Steps:

1 Synthesis of 2,4-dichloro-5-nitro-pyridine

NaOH (6.60 g, 165 mmol) was dissolved in H₂O (31 mL) and cooled in an ice bath. Bromine (2.08 mL, 40.6 mmol) was added dropwise and the yellow solution was stirred for 15 min. 4,6-Dichloro-nicotinamide (7.27 g, 38.1 mmol) in 1,4-dioxane (21 mL) was added dropwise to the bromine solution over 30 min. The reaction was allowed to warm slowly to 25° C. over 18 h. The volatiles were removed in vacuo and the resultant solution was diluted with brine and poured into EtOAc. The aqueous phase was separated and extracted twice with EtOAc. The organic layers were combined, dried (Na₂SO₄), decanted and concentrated to afford an orange oil. The resultant oil was purified on a 100 g SiO₂ flash chromatography cartridge with 25 % EtOAc-hexanes to afford 4,6-dichloro-pyridin-3-ylamine as a tan solid (4.54 g, 73%). 30% Aqueous H₂O₂ solution (29 mL) was cooled in an ice bath.

References:

US2006/217417,2006,A1 Location in patent:Page/Page column 13