N-Fluorobenzenesulfonimide → 3-Fluoro-6-trifluoromethyl-benzo[b]thiophene-2-carboxylic acid

HRID 409905Notes

Reaction equation

HRID 409905 reaction equation
[F:1][C:2]([F:16])([F:15])[C:3]1[CH:4]=[CH:5][C:6]2[CH:10]=[C:9]([C:11]([OH:13])=[O:12])[S:8][C:7]=2[CH:14]=1.[Li]CCCC.C1C=CC(S(N(S(C2C=CC=CC=2)(=O)=O)[F:32])(=O)=O)=CC=1>C1COCC1>[F:32][C:10]1[C:6]2[CH:5]=[CH:4][C:3]([C:2]([F:15])([F:1])[F:16])=[CH:14][C:7]=2[S:8][C:9]=1[C:11]([OH:13])=[O:12]

Participants

5

Reactant 3

HCID 588007N-FluorobenzenesulfonimideHCID 179795236-(Trifluoromethyl)benzo[b]thiophene-2-carboxylic acidHCID 178418339Butyllithium

Product 1

HCID 596258883-Fluoro-6-trifluoromethyl-benzo[b]thiophene-2-carboxylic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of 6-trifluoromethyl-benzo[b]thiophene-2-carboxylic acid 15a (2.031 mmol, 0.50 g) in THF (8 mL) at −70° C. was treated with a 1.6 M solution of n-BuLi in hexanes (4.26 mmol, 2.66 mL). After 1 h at −70° C., N-fluorobenzenesulfonimide (2.64 mmol, 0.833 g) in THF (2 mL) was slowly added and the reaction was warmed to room temperature. After 1 h the mixture was partitioned between dilute aqueous HCl and EtOAc. The organic layer was washed with water and brine, and then concentrated. The residue was triturated with CH2Cl2. The off-white precipitate was filtered and collected to provide 15b.

Workup

  1. customAfter 1 h the mixture was partitioned between dilute aqueous HCl and EtOAc
  2. washThe organic layer was washed with water and brine
  3. concentrationconcentrated
  4. customThe residue was triturated with CH2Cl2
  5. filtrationThe off-white precipitate was filtered
  6. customcollected

Sources & evidence

ORD record
ord-8b64c114548741309322f298cbcaf4db
Source dataset
uspto-grants-2014_06
Patent number
US08759533B2

Reaction notes

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