Sulfuric Acid → 2-Chloro-5-bromo-6-fluorobenzamide

HRID 1593970Notes

Reaction equation

HRID 1593970 reaction equation
S(=O)(=O)(O)O.[Br:6][C:7]1[C:8]([F:16])=[C:9]([C:12]([Cl:15])=[CH:13][CH:14]=1)[C:10]#[N:11].[OH-:17].[NH4+]>>[Br:6][C:7]1[C:8]([F:16])=[C:9]([C:12]([Cl:15])=[CH:13][CH:14]=1)[C:10]([NH2:11])=[O:17]

Participants

4

Conditions

Temperature
55 °C

Procedure

Concentrated sulfuric acid (15 mL) was placed in a 100 mL 3-neck flask equipped with an internal thermometer and heated to 55° C. 3-Bromo-2-fluoro-6-chlorobenzonitrile (11.0 g, 47 mmol) was added portion-wise to the acid with stirring maintaining the temperature above 50° C. The dark solution was heated at 65° C. for 24 hours, allowed to cool to room temperature, poured over ice, and cautiously neutralized with concentrated ammonium hydroxide. The mixture was extracted with two portions of ethyl acetate and the combined organic layers were dried and concentrated to give 3-bromo-2-fluoro-6-chlorobenzamide (11.5 g, 45.5 mmol) as a light orange solid: mp 157-158° C., 1H NMR (CDCl3): δ 7.54 (t, 1H), 7.14 (dd, 1H), 6.03 (br s, 1H) 5.81 (br s, 1H).

Workup

  1. customequipped with an internal thermometer
  2. temperaturemaintaining the temperature above 50° C
  3. temperatureThe dark solution was heated at 65° C. for 24 hours
  4. temperatureto cool to room temperature
  5. additionpoured over ice
  6. extractionThe mixture was extracted with two portions of ethyl acetate
  7. customthe combined organic layers were dried
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-3cae0e5a481747f1ba35276727a96f25
Source dataset
uspto-grants-2007_11
Patent number
US07300907B2

Reaction notes

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