Hydrochloric Acid → 2-(2-Hydroxy-3,3,3-trifluoropropyl)-3,4-dihydro-2H-1-benzopyran

HRID 582602Notes

Reaction equation

HRID 582602 reaction equation
[O:1]1[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][C:5]=2[CH2:4][CH2:3][CH:2]1[CH2:11][CH:12]=[O:13].[F:14][C:15]([F:21])([F:20])[Si](C)(C)C.Cl>O1CCCC1.[F-].C([N+](CCCC)(CCCC)CCCC)CCC>[OH:13][CH:12]([C:15]([F:21])([F:20])[F:14])[CH2:11][CH:2]1[CH2:3][CH2:4][C:5]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=2[O:1]1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 552549(Trifluoromethyl)trimethylsilaneHCID 544771563,4-dihydro-2H-1-benzopyran-2-acetaldehyde

Product 1

HCID 153456652-(2-Hydroxy-3,3,3-trifluoropropyl)-3,4-dihydro-2H-1-benzopyranYield 81.2%

Reagents, catalysts & solvents 2

HCID 2724141Tetrabutylammonium FluorideCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 7.6 g (43 mmol) of 3,4-dihydro-2H-1-benzopyran-2-acetaldehyde in 110 ml of tetrahydrofuran are added dropwise, at -10° C., 7.1 ml (52 mmol) of trifluorotrimethylsilylmethane and a solution of 90 mg (2 mg/mmol) of tetrabutylammonium fluoride in 5 ml of tetrahydrofuran. The mixture is allowed to react for 2 hours at 0° C., then it is hydrolyzed for 2 hours using a 1M solution of hydrochloric acid and the product is extracted with diethyl ether. The organic phase is then washed with water, dried over sodium sulfate and then concentrated under reduced pressure. By chromatography of the residue on a silica column using a 50/50 mixture of dichloromethane and of cyclohexane, 8.6 g of product are obtained in oil form.

Workup

  1. customto react for 2 hours at 0° C.
  2. extractionthe product is extracted with diethyl ether
  3. washThe organic phase is then washed with water
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated under reduced pressure
  6. additiona 50/50 mixture of dichloromethane

Sources & evidence

ORD record
ord-eb48174f8fa34aa7aee5a4256f348f3b
Source dataset
uspto-grants-1999_07
Patent number
US05925662

Reaction notes

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