Hydrogen Bromide → HCID 19037035, compound

HRID 264851Notes

Reaction equation

HRID 264851 reaction equation
S(=O)(=O)(O)O.N([O-])=O.[Na+].N[C:11]1[CH:12]=[CH:13][C:14]2[O:19][C:18]([CH2:22][F:23])([CH2:20][F:21])[CH:17]=[C:16]([C:24]#[N:25])[C:15]=2[CH:26]=1.[BrH:27].[Br-].[Na+].S([O-])([O-])=O.[Na+].[Na+]>O.O.O.O.O.S([O-])([O-])(=O)=O.[Cu+2].O.C(O)(=O)C>[Br:27][C:11]1[CH:12]=[CH:13][C:14]2[O:19][C:18]([CH2:22][F:23])([CH2:20][F:21])[CH:17]=[C:16]([C:24]#[N:25])[C:15]=2[CH:26]=1

Participants

10

Reactant 6

HCID 260Hydrogen BromideHCID 1118Sulfuric AcidHCID 24437Sodium SulfiteHCID 253881Sodium BromideHCID 19037078HCID 19037078, compoundHCID 23668193Sodium Nitrite

Product 1

HCID 19037035HCID 19037035, compound

Reagents, catalysts & solvents 3

HCID 24463Copper sulfate pentahydrateCatalystHCID 176Acetic AcidSolventHCID 962WaterSolvent

Procedure

10 ml of concentrated sulfuric acid was heated at 40° C. and 760 mg of sodium nitrite acid was added therein. Then, the reaction solution was cooled to room temperature and 20 ml of an acetic acid solution of 2.0 g of 6-amino-4-cyano-2,2-bis(fluoromethyl)-2H-1-benzopyran was added therein. The reaction solution was dropped into 12 ml of an aqueous hydrobromic acid solution of cuprous bromide prepared in advance from 4.2 g of copper (II) sulfate pentahydrate, 2.6 g of sodium bromide and 1.1 g of sodium sulfite under ice-cooling. The resultant mixture was heated to room temperature and stirred for 1 hour. Water was added therein and the mixture was extracted with methylene chloride. An organic layer was washed with an aqueous 2N hydrochloric acid solution and an aqueous 1N sodium hydroxide solution and dried. The solvent was distilled. The obtained residue was purified according to silica gel column chromatography (developing solution, AcOH:hexane=1:5) and recrystallized by a mixed solvent of ethyl acetate and hexane to obtain 690 mg of 6-bromo-4-cyano-2,2-bis(fluoromethyl)-2H-1-benzopyran with a melting point of 105°-107° C.

Workup

  1. temperaturecooling
  2. extractionthe mixture was extracted with methylene chloride
  3. washAn organic layer was washed with an aqueous 2N hydrochloric acid solution
  4. dry with materialan aqueous 1N sodium hydroxide solution and dried
  5. distillationThe solvent was distilled
  6. customThe obtained residue was purified
  7. customrecrystallized by a mixed solvent of ethyl acetate and hexane

Sources & evidence

ORD record
ord-400246d4f16f4987941146feaac63e93
Source dataset
uspto-grants-1997_07
Patent number
US05646308

Reaction notes

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