반응 #584983

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2-Amino-5-bromopyridine

sodium hydroxide

sulfuric acid

periodic acid hydrate

periodic acid hydrate

iodine

→

2-amino-5-bromo-3-iodopyridine

수율 76.0%

용매

water

acetic acid

반응 조건

후처리

1. 1
   workup.DISSOLUTION1072-97-5) (300 g) was dissolved in a mixed solvent
2. 2
   workup.ADDITIONwere gradually dropped
3. 3
   workup.STIRRINGby stirring at 80° C. for 4 hours
4. 4
   workup.STIRRINGby further stirring at 80° C. for 2 hours
5. 5
   workup.ADDITIONthe reaction mixture was poured onto ice (3000 ml)
6. 6
   여과The resulting crystals were collected by filtration
7. 7
   workup.DISSOLUTIONdissolved in a mixed solvent of ethyl acetate/diethyl ether
8. 8
   세척successively washed with aqueous sodium thiosulfate, water, 1N aqueous sodium hydroxide and brine
9. 9
   건조dried over anhydrous magnesium sulfate
10. 10
    기타Then, the solvent was evaporated

실험 절차

2-Amino-5-bromopyridine (CAS No. 1072-97-5) (300 g) was dissolved in a mixed solvent consisting of 1000 ml of acetic acid and 200 ml of water, 30 ml of concentrated sulfuric acid were gradually dropped thereinto under stirring. Then, 79.1 g of periodic acid hydrate and 176 g of iodine were added thereto, followed by stirring at 80° C. for 4 hours. To the reaction mixture were added periodic acid hydrate (40 g) and iodine (22 g), followed by further stirring at 80° C. for 2 hours. After cooling to room temperature, the reaction mixture was poured onto ice (3000 ml) and neutralized to pH 7.0 with 5N aqueous sodium hydroxide. The resulting crystals were collected by filtration, dissolved in a mixed solvent of ethyl acetate/diethyl ether, successively washed with aqueous sodium thiosulfate, water, 1N aqueous sodium hydroxide and brine, and dried over anhydrous magnesium sulfate. Then, the solvent was evaporated, to give 392 g of 2-amino-5-bromo-3-iodopyridine (yield: 76%). 2-Amino-5-bromo-3-iodopyridine (100 g) was gradually added to 300 ml of concentrated sulfuric acid under ice-cooling. After the reaction mixture was stirred at room temperature for 2 hours, it was ice-cooled again. 35 g of sodium nitrite were gradually added thereto, followed by stirring at room temperature for 3 days and nights. The reaction solution was poured onto ice (3000 ml) and neutralized to pH 4.0 with sodium hydroxide. The resulting crystals were collected by filtration, washed with water and warm air-dried at 60° C. for one day and night, to give 102 g (quantitative) of the title compound.

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