Water → 8-amino-3,4-dihydro-7-fluoro-2H-1-benzopyran

HRID 440687Notes

Reaction equation

HRID 440687 reaction equation
FC(F)(F)C(O)=O.[F:8][C:9]1[CH:18]=[CH:17][C:12]2[CH2:13][CH2:14][CH2:15][O:16][C:11]=2[C:10]=1[NH:19]C(=O)OC(C)(C)C.O.C(=O)(O)[O-].[Na+]>C(OCC)C>[NH2:19][C:10]1[C:11]2[O:16][CH2:15][CH2:14][CH2:13][C:12]=2[CH:17]=[CH:18][C:9]=1[F:8]

Participants

6

Reactant 4

HCID 962WaterHCID 6422Trifluoroacetic acidHCID 516892Sodium BicarbonateHCID 224047711,1-dimethylethyl N-(3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)carbamate

Product 1

HCID 224047958-amino-3,4-dihydro-7-fluoro-2H-1-benzopyranYield 96.2%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

Trifluoroacetic acid, 50 mL, was stirred and cooled in an ice-water bath, and 6.1 grams (0.023 mole) of 1,1-dimethylethyl N-(3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)carbamate was added portionwise. Upon completion of the addition, the reaction mixture was stirred for one hour, then stirred with water and diethyl ether and neutralized with solid sodium bicarbonate. The water layer was separated and extracted with diethyl ether. The extract was combined with the organic layer, and the combination was washed with water. The organic layer was dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure, yielding 3.7 grams of 8-amino-3,4-dihydro-7-fluoro-2H-1-benzopyran. The NMR spectrum was consistent with the proposed structure.

Workup

  1. temperaturecooled in an ice-water bath
  2. additionUpon completion of the addition
  3. customThe water layer was separated
  4. extractionextracted with diethyl ether
  5. washthe combination was washed with water
  6. dry with materialThe organic layer was dried with magnesium sulfate
  7. filtrationfiltered
  8. concentrationThe filtrate was concentrated under reduced pressure

Sources & evidence

ORD record
ord-0fb692180f8340cc933309255eaaf267
Source dataset
uspto-grants-1996_05
Patent number
US05521147

Reaction notes

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