Hydrogen Bromide → Benzoic acid, 3-bromo-4-chloro-2-methyl-, ethyl ester
Reaction equation
N([O-])=O.[Na+].N[C:6]1[C:7]([CH3:18])=[C:8]([CH:14]=[CH:15][C:16]=1[Cl:17])[C:9]([O:11][CH2:12][CH3:13])=[O:10].C(OCC)(=O)C.[BrH:25]>S(=O)(=O)(O)O.C(O)(=O)C.O.[Cu]Br>[Br:25][C:6]1[C:7]([CH3:18])=[C:8]([CH:14]=[CH:15][C:16]=1[Cl:17])[C:9]([O:11][CH2:12][CH3:13])=[O:10]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 4
Conditions
- Temperature
- 5 °C
Procedure
A solution of sodium nitrite (13 g) in concentrated sulphuric acid was added during 0.5 hours to a solution of ethyl 3-amino-4-chloro-2-methylbenzoate (22.4 g) in acetic acid, keeping the temperature below 15° C. After stirring for a further 1 hour at 5° C., the resulting diazonium mixture was added during 0.75 hours to a solution of copper (I) bromide (31 g) in hydrobromic acid (45%, 103 ml) and water. Heating to 40° C. was continued for a further 2 hours before addition of water and extraction (ethyl acetate). The extract was washed (sodium hydroxide solution), dried (magnesium sulphate) and evaporated to give ethyl 3-bromo-4-chloro-2-methylbenzoate (22.2 g) as a brown oil, NMR (CDCl3) 1.3 (t,3H), 2.65 (s,3H), 4.3 (q,2H), 7.45 (m,2H).
Workup
- customthe temperature below 15° C
- temperatureHeating to 40° C.
- washThe extract was washed (sodium hydroxide solution)
- dry with materialdried (magnesium sulphate)
- customevaporated
Sources & evidence
- ORD record
- ord-679e892a7e9e4c22a0a62553ebfc1439
- Source dataset
- uspto-grants-1994_12
- Patent number
- US05374606
Reaction notes
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