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

HRID 2419315Notes

Reaction equation

HRID 2419315 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-04b58c2bd993489aab38d9f2ee2ac781
Source dataset
uspto-grants-1978_08
Patent number
US04105767

Reaction notes

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