Nitric Acid → 6-Bromo-3-nitroimidazo[1,2-a]pyridine

HRID 839636Notes

Reaction equation

HRID 839636 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH:8]=[CH:9][N:10]=2)[CH:7]=1.S(=O)(=O)(O)O.[N+:16]([O-])([OH:18])=[O:17].[OH-].[K+]>>[N+:16]([C:8]1[N:6]2[CH:7]=[C:2]([Br:1])[CH:3]=[CH:4][C:5]2=[N:10][CH:9]=1)([O-:18])=[O:17]

Participants

5

Reactant 4

HCID 944Nitric AcidHCID 1118Sulfuric AcidHCID 14797Potassium HydroxideHCID 27955476-Bromoimidazo[1,2-a]pyridine

Product 1

HCID 288758886-Bromo-3-nitroimidazo[1,2-a]pyridine

Procedure

A solution of 24 gms. (.122 mole) of 6-bromoimidazo [1,2-a] pyridine in 80 ml. of concentrated sulfuric acid is treated dropwise with 24 ml. of concentrated nitric acid while maintaining a temperature of 15° C. with external cooling. When the addition is complete, the reaction mixture is stirred at room temperature for 1/2 hour and poured onto 450 gm. of ice. The ph of the mixture is adjusted to ph 4 with aqueous potassium hydroxide and the resultant solids are collected by filtration. The filter cake is washed with water and dried. Recrystallization from methylene chloride-hexane yields pure 3-nitro 6-bromoimidazo [1,2-a] pyridine m.p. 160°-161° C.

Workup

  1. additionWhen the addition
  2. additionpoured onto 450 gm
  3. filtrationthe resultant solids are collected by filtration
  4. washThe filter cake is washed with water
  5. customdried
  6. customRecrystallization from methylene chloride-hexane

Sources & evidence

ORD record
ord-f3183e9fface4f36b10a474e54372db7
Source dataset
uspto-grants-1978_06
Patent number
US04096264

Reaction notes

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