Water → 3-(2-Aminoethyl)-2,2-dimethyl-6-fluoro-chroman

HRID 1196059Notes

Reaction equation

HRID 1196059 reaction equation
[N:1]([CH2:4][CH2:5][CH:6]1[CH2:15][C:14]2[C:9](=[CH:10][CH:11]=[C:12]([F:16])[CH:13]=2)[O:8][C:7]1([CH3:18])[CH3:17])=[N+]=[N-].[H-].[Al+3].[Li+].[H-].[H-].[H-].O.[OH-].[Na+]>O1CCCC1.C(OCC)C>[NH2:1][CH2:4][CH2:5][CH:6]1[CH2:15][C:14]2[C:9](=[CH:10][CH:11]=[C:12]([F:16])[CH:13]=2)[O:8][C:7]1([CH3:18])[CH3:17]

Participants

7

Reactant 4

HCID 962Water2×HCID 14798Sodium HydroxideHCID 21226445Aluminium lithium hydrideHCID 543835353-(2-Azidoethyl)-2,2-dimethyl-6-fluorochroman

Product 1

HCID 538627943-(2-Aminoethyl)-2,2-dimethyl-6-fluoro-chroman

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 4.0 g (16 mmol) of 3-(2-azidoethyl)-2,2-dimethyl-6-fluoro-chroman in 30 ml of absolute tetrahydrofuran is added dropwise within a period of 30 minutes to a suspension of 0.61 g (16 mmol) of lithium aluminium hydride in 30 ml of absolute diethyl ether. The reaction mixture is then stirred for 2 hours at room temperature and then carefully decomposed with 0.61 ml of water, 0.61 ml of sodium hydroxide solution (15%) and 1.83 ml of water. The resulting precipitate is filtered off with suction and the filtrate is concentrated by evaporation in vacuo. The oily residue is dissolved in diethyl ether and the solution is extracted with 2N hydrochloric acid. The combined hydrochloric acid extracts are rendered alkaline with sodium hydroxide solution (30%) while cooling with ice and extracted with dichloromethane. The combined dichloromethane phases are dried over sodium sulfate and concentrated by evaporation in vacuo, yielding 3.21 g (90% of the theoretical yield) of 3-(2 -aminoethyl)-2,2-dimethyl-6-fluoro-chroman in the form of a yellow oil. 3-(2-aminoethyl)-2,2-dimethyl-6-fluoro-chroman hydrochloride, prepared therefrom with hydrochloric acid in diethyl ether, crystallises from methanol/diethyl ether and has a melting range of from 249° to 251°.

Workup

  1. filtrationThe resulting precipitate is filtered off with suction
  2. concentrationthe filtrate is concentrated by evaporation in vacuo
  3. dissolutionThe oily residue is dissolved in diethyl ether
  4. extractionthe solution is extracted with 2N hydrochloric acid
  5. temperaturewhile cooling with ice
  6. extractionextracted with dichloromethane
  7. dry with materialThe combined dichloromethane phases are dried over sodium sulfate
  8. concentrationconcentrated by evaporation in vacuo
  9. customyielding 3.21 g (90% of the

Sources & evidence

ORD record
ord-5a5d7e43545f468f84565bfcda889480
Source dataset
uspto-grants-1992_05
Patent number
US05112855

Reaction notes

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