Hydrochloric Acid → 5-Methoxy-2-nitro-1,1'-biphenyl

HRID 1464043Notes

Reaction equation

HRID 1464043 reaction equation
[N+:1]([C:4]1[CH:10]=[CH:9][C:8]([O:11][CH3:12])=[CH:7][C:5]=1N)([O-:3])=[O:2].Cl.N([O-])=O.[Na+]>O>[CH3:12][O:11][C:8]1[CH:9]=[CH:10][C:4]([N+:1]([O-:3])=[O:2])=[C:5]([C:4]2[CH:10]=[CH:9][CH:8]=[CH:7][CH:5]=2)[CH:7]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 853005-Methoxy-2-nitroanilineHCID 23668193Sodium Nitrite

Product 1

HCID 154865975-Methoxy-2-nitro-1,1'-biphenyl

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A suspension of 2-nitro-5-methoxyaniline (3.7 g) in water (25 ml) was heated at 80° C. with 36% hydrochloric acid (7.7 ml) for 30 minutes. It was then treated dropwise with aqueous sodium nitrite solution (1.8 g in 5 ml H2O) at 0° C. After 1 hour, the mixture was filtered and the filtrate added at 23° C. to a solution of dimethylamine (35% aqueous solution, 3.9 ml) and sodium carbonate (8.2 g) in water (340 ml). After 12 hours at 23° C. a solid was collected by filtration and dissolved in benzene (100 ml). The solution was heated under reflux and treated with p-toluene sulphonic acid (4.0 g) and heated under reflux for 4 hours in a Dean-Stark water separator. The reaction mixture stood for 48 hours and was then partitioned between cold 10% aqueous sodium hydroxide solution and dichloromethane. Evaporation of the organic layer left an oil which was purified on silica column using ethylacetate:hexane as eluant to furnish 5-methoxy-2-nitrobiphenyl which was dissolved in ethanol (30 ml) and heated under reflux with sodium sulphide (5.3 g) for 8 hours. Purification of the product on a silica column gave 2-amino-5-methoxybiphenyl which was converted into its hydro-chloride salt (m.p. 167° C.).

Workup

  1. filtrationthe mixture was filtered
  2. additionthe filtrate added at 23° C. to a solution of dimethylamine (35% aqueous solution, 3.9 ml) and sodium carbonate (8.2 g) in water (340 ml)
  3. filtrationAfter 12 hours at 23° C. a solid was collected by filtration
  4. dissolutiondissolved in benzene (100 ml)
  5. temperatureThe solution was heated
  6. temperatureunder reflux
  7. additiontreated with p-toluene sulphonic acid (4.0 g)
  8. temperatureheated
  9. temperatureunder reflux for 4 hours in a Dean-Stark water separator
  10. waitThe reaction mixture stood for 48 hours
  11. customwas then partitioned between cold 10% aqueous sodium hydroxide solution and dichloromethane
  12. customEvaporation of the organic layer
  13. waitleft an oil which
  14. customwas purified on silica column

Sources & evidence

ORD record
ord-250ccb0783714a72bd4d41da25511eca
Source dataset
uspto-grants-1994_04
Patent number
US05302720

Reaction notes

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