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

HRID 258569Notes

Reaction equation

HRID 258569 reaction equation
[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

Participants

6

Reactant 5

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 24526ChlorineHCID 706222-Amino-5-bromopyridineHCID 23665763Sodium Bisulfite

Product 1

HCID 123706695-Bromo-3-chloropyridin-2-amineYield 95.4%

Procedure

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.

Workup

  1. customAfter complete reaction
  2. additionWhilst ice is added
  3. filtrationthe precipitate is then filtered off
  4. washwashed with water
  5. customRecrystallisation from cyclohexane

Sources & evidence

ORD record
ord-84d6022fc80a4243817b83f98cb4fe81
Source dataset
uspto-grants-1977_07
Patent number
US04033975

Reaction notes

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