Sulfuric Acid → ethyl 2,2-bisfluoromethyl-6-iodo-2H-1-benzopyran-4-carboxylate

HRID 264823Notes

Reaction equation

HRID 264823 reaction equation
N([O-])=O.[Na+].N[C:6]1[CH:7]=[CH:8][C:9]2[O:14][C:13]([CH2:17][F:18])([CH2:15][F:16])[CH:12]=[C:11]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:10]=2[CH:24]=1.S(=O)(=O)(O)O.[I-:30].[K+]>CCCCCC.C(OCC)(=O)C.O.C(Cl)Cl>[F:16][CH2:15][C:13]1([CH2:17][F:18])[CH:12]=[C:11]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:10]2[CH:24]=[C:6]([I:30])[CH:7]=[CH:8][C:9]=2[O:14]1

Participants

9

Reactant 4

HCID 1118Sulfuric AcidHCID 4875Potassium IodideHCID 19037020ethyl 6-amino-2,2-bisfluoromethyl-2H-1-benzopyran-4-carboxylateHCID 23668193Sodium Nitrite

Product 1

HCID 19037016ethyl 2,2-bisfluoromethyl-6-iodo-2H-1-benzopyran-4-carboxylateYield 65.9%

Reagents, catalysts & solvents 4

HCID 962WaterSolvent4×HCID 6344DichloromethaneSolventHCID 8058HexaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

A mixture of 1.09 g of sodium nitrite, 10 ml of methylene chloride and 10 ml of water was added to a mixture of 4.0 g of ethyl 6-amino-2,2-bisfluoromethyl-2H-1-benzopyran-4-carboxylate, 1.66 g of sulfuric acid and 40 ml of water under ice cooling, followed by stirring under ice cooling for 10 minutes. Further, a mixture of 2.85 g of potassium iodide and 5 ml of water was added to the reaction mixture, followed by stirring at room temperature for 1.5 hour. Water was added to the reaction mixture, and the mixture was extracted with methylene chloride. The organic layer was washed with a 20% aqueous solution of sodium sulfite and a brine and then dried over sodium sulfate. The residue obtained by concentration under reduced pressure was subjected to silica gel column chromatography (an eluting solvent, ethyl acetate:hexane=1:1) to obtain 3.67 g of ethyl 2,2-bisfluoromethyl-6-iodo-2H-1-benzopyran-4-carboxylate having a melting point of 89°-90° C.

Workup

  1. additionwas added to the reaction mixture
  2. stirringby stirring at room temperature for 1.5 hour
  3. extractionthe mixture was extracted with methylene chloride
  4. washThe organic layer was washed with a 20% aqueous solution of sodium sulfite
  5. dry with materiala brine and then dried over sodium sulfate
  6. customThe residue obtained by concentration under reduced pressure

Sources & evidence

ORD record
ord-396308a5c7c94194a0dbdaf1402b389f
Source dataset
uspto-grants-1997_07
Patent number
US05646310

Reaction notes

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