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

HRID 1782606Notes

Reaction equation

HRID 1782606 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

Reactant 3

HCID 1118Sulfuric AcidHCID 14923Ammonium HydroxideHCID 509979493-Bromo-6-chloro-2-fluorobenzonitrile

Product 1

HCID 184515062-Chloro-5-bromo-6-fluorobenzamide

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 then 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 then cooled to room temperature and 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 dried over Na2SO4 (with charcoal). Filtration and concentration gave 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 (bs, 1H) 5.81 (bs, 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. temperaturethen cooled to room temperature
  5. additionpoured over ice
  6. extractionThe mixture was extracted with two portions of ethyl acetate
  7. dry with materialthe combined organic layers dried over Na2SO4 (with charcoal)
  8. filtrationFiltration and concentration

Sources & evidence

ORD record
ord-0e2fd3470e2344a3b83e5e13d3941608
Source dataset
uspto-grants-2009_03
Patent number
US07498468B2

Reaction notes

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