Hypophosphoric acid → Methyl 3-bromo-5-methoxybenzoate

HRID 1453643Notes

Reaction equation

HRID 1453643 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([O:13][CH3:14])[C:11]=1N)[C:5]([O:7][CH3:8])=[O:6].N([O-])=O.[Na+].P(P(O)(O)=O)(O)(O)=O>C(O)C.S(=O)(=O)(O)O.C(O)(=O)C.O>[Br:1][C:2]1[CH:3]=[C:4]([CH:9]=[C:10]([O:13][CH3:14])[CH:11]=1)[C:5]([O:7][CH3:8])=[O:6]

Participants

8

Reactant 3

HCID 24536Hypophosphoric acidHCID 22324265Methyl 4-amino-3-bromo-5-methoxybenzoateHCID 23668193Sodium Nitrite

Product 1

HCID 15618226Methyl 3-bromo-5-methoxybenzoateYield 100.2%

Reagents, catalysts & solvents 4

HCID 176Acetic AcidSolventHCID 702EthanolSolventHCID 962WaterSolvent2×HCID 1118Sulfuric AcidSolvent

Procedure

A 500 ml round bottom flask fitted with overhead stirring was charged with 16.5 grams (55 mmole) of methyl 3-bromo-5-methoxy-4-aminobenzoate in 80 ml ethanol, 15 ml sulfuric acid and 20 ml acetic acid. The solution was chilled in an ice bath and 6.6 gms (95 mmole) of sodium nitrite in 30 ml water was added dropwise while maintaining the temperature below 10° C. After stirring an additional 25 minutes, 100 ml of 50% hypophosphoric acid was added and the mixture was stirred cold for 2 hours. The reaction mixture was diluted with 500 ml water, extracted with ether, and then evaporated under reduced pressure to give 13.5 grams of methyl 3-bromo-5-methoxybenzoate as a reddish-oil.

Workup

  1. customA 500 ml round bottom flask fitted with overhead
  2. temperatureThe solution was chilled in an ice bath
  3. temperaturewhile maintaining the temperature below 10° C
  4. stirringAfter stirring an additional 25 minutes
  5. stirringthe mixture was stirred cold for 2 hours
  6. extractionextracted with ether
  7. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-4054181d9e8b4303af4d6fe20227486b
Source dataset
uspto-grants-2009_01
Patent number
US07476675B2

Reaction notes

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