Hydrogen Bromide → Methyl 2-amino-5-bromo-3-methylbenzoate

HRID 1753996Notes

Reaction equation

HRID 1753996 reaction equation
[NH2:1][C:2]1[C:11]([CH3:12])=[CH:10][CH:9]=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].[BrH:13].OO.OS([O-])=O.[Na+].C([O-])([O-])=O.[Na+].[Na+]>O>[NH2:1][C:2]1[C:11]([CH3:12])=[CH:10][C:9]([Br:13])=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5]

Participants

7

Reactant 5

HCID 260Hydrogen BromideHCID 784Hydrogen PeroxideHCID 10340Sodium CarbonateHCID 2763406Methyl 3-methylanthranilateHCID 23665763Sodium Bisulfite

Product 1

HCID 2763413Methyl 2-amino-5-bromo-3-methylbenzoate

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A solution of methyl 2-amino-3-methylbenzoate (142.1 g, 0.843 mol, purity: 98% quantitative NMR) in 240 mL of H2O is gradually admixed at 30° C. with hydrogen bromide (48% of H2O, 149.2 g, 0.885 mol) added dropwise. The suspension obtained is admixed with hydrogen peroxide (30% in H2O, 105.1 g, 0.927 mol) added dropwise over 2 h, and the temperature is kept below 70° C. After 1 hour of subsequent stirring, NaHSO3 (39% in H2O, 33.7 g, 0.126 mol) is added a little at a time (peroxide test was negative). The suspension obtained is adjusted to pH7-8 with Na2CO3 (0.1 eq., 9.0 g, 0.084 mol), which is added a little at a time. Following filtration and drying in a vacuum drying cabinet, methyl 2-amino-5-bromo-3-methylbenzoate is isolated as a pale brown solid. Yield: 204.2 g, 97.7% of theory, purity: 98.5% quantitative NMR).

Workup

  1. additionadded dropwise
  2. customThe suspension obtained
  3. additionadded dropwise over 2 h
  4. customis kept below 70° C
  5. customThe suspension obtained
  6. additionis added a little at a time
  7. filtrationfiltration
  8. customdrying in a vacuum
  9. customdrying cabinet

Sources & evidence

ORD record
ord-27e3c7c4c7804df4aae88fe42b94aea2
Source dataset
uspto-grants-2015_10
Patent number
US09169198B2

Reaction notes

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