Hydrochloric Acid → 5-Bromo-3-chloropyridin-2-amine

反応式

[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([Br:8])=[CH:4][N:3]=1.[ClH:9].ClCl.S(=O)(O)[O-].[Na+].[OH-].[Na+]>>[NH2:1][C:2]1[C:7]([Cl:9])=[CH:6][C:5]([Br:8])=[CH:4][N:3]=1

参加物

反応物 5

HCID 313Hydrochloric Acid

HCID 14798Sodium Hydroxide

HCID 24526Chlorine

HCID 706222-Amino-5-bromopyridine

HCID 23665763Sodium Bisulfite

生成物 1

HCID 123706695-Bromo-3-chloropyridin-2-amine収率 95.4%

実験手順

To produce 2-amino-3-chloro-5-bromopyridine, chlorine is slowly introduced in the course of 8 hours at about 50° C. into a solution of 25 parts of 2-amino-5-bromopyridine in 70 parts of concentrated hydrochloric acid. After complete reaction, the solution is poured into ice-water, and the unreacted chlorine is decomposed with sodium bisulphite. Whilst ice is added, the solution is adjusted at 15° with 30% sodium hydroxide solution to pH 8 and subsequently stirred for one hour; the precipitate is then filtered off and washed with water. Recrystallisation from cyclohexane yields 28.5 parts (95.4% of theory) of 2-amino-3-chloro-5-bromopyridine in the form of white needles, m.p. 94°-96° C.