N-methyl-2-pyrrolidone → 5-Chloro-4-fluoro-2-hydroxybenzoic acid

HRID 1276825Notes

Reaction equation

HRID 1276825 reaction equation
[Cl:1][C:2]1[C:3]([F:12])=[CH:4][C:5](F)=[C:6]([CH:10]=1)[C:7]([OH:9])=[O:8].[OH-].[Na+].CN1CCCC1=[O:21]>O>[Cl:1][C:2]1[CH:10]=[C:6]([C:7]([OH:9])=[O:8])[C:5]([OH:21])=[CH:4][C:3]=1[F:12]

Participants

5

Reactant 3

HCID 13387N-methyl-2-pyrrolidone2×HCID 14798Sodium HydroxideHCID 148764175-Chloro-2,4-difluorobenzoic acid

Product 1

HCID 221167895-Chloro-4-fluoro-2-hydroxybenzoic acidYield 92.1%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
130 °C

Procedure

1.93 g (0.01 mole) of 5-chloro-2,4-difluorobenzoic acid, 1.62 g (0.04 mole) of powdery 99% sodium hydroxide and 20 ml of 1-methyl-2-pyrrolidone were fed into a 100-ml four-necked flask provided with a thermometer, a stirrer and a reflux condenser. The mixture was stirred at 130° C. for 3 hours to give rise to a reaction. After the completion of the reaction, part of 1-methyl-2-pyrrolidone was recovered. The resulting reaction mixture was diluted with 500 ml of water and then subjected to precipitation with a 10% aqueous hydrochloric acid solution. The resulting crystals were collected by filtration, washed with water, and dried to obtain 1.76 g of 5-chloro-4-fluorosalicylic acid. The isolated yield was 92.1% relative to the 5-chloro-2,4-difluorobenzoic acid used.

Workup

  1. customprovided with a thermometer, a stirrer and a reflux condenser
  2. customto give rise
  3. customto a reaction
  4. customwas recovered
  5. customThe resulting reaction mixture
  6. customsubjected to precipitation with a 10% aqueous hydrochloric acid solution
  7. filtrationThe resulting crystals were collected by filtration
  8. washwashed with water
  9. customdried

Sources & evidence

ORD record
ord-d57ad6c1e5ae494e9c1484a485cf0ab0
Source dataset
uspto-grants-2000_12
Patent number
US06166246

Reaction notes

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