Sodium Hydroxide → 2-(3,4-dihydro-2H-1-benzopyran-3-yl)ethan-1-amine

HRID 1196006Notes

Reaction equation

HRID 1196006 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[H-].[Al+3].[Li+].[H-].[H-].[H-].[C:11]([CH2:13][CH:14]1[CH2:23][C:22]2[C:17](=[CH:18][CH:19]=[CH:20][CH:21]=2)[O:16][CH2:15]1)#[N:12].[OH-].[Na+]>C(OCC)C.O1CCCC1.O>[NH2:12][CH2:11][CH2:13][CH:14]1[CH2:23][C:22]2[C:17](=[CH:18][CH:19]=[CH:20][CH:21]=2)[O:16][CH2:15]1

Participants

8

Reactant 4

HCID 14798Sodium HydroxideHCID 6451240Aluminum(III) ChlorideHCID 14838407Chroman-3-yl-acetonitrileHCID 21226445Aluminium lithium hydride

Product 1

HCID 148384082-(3,4-dihydro-2H-1-benzopyran-3-yl)ethan-1-amineYield 90%

Reagents, catalysts & solvents 3

HCID 962WaterSolvent2×HCID 3283Diethyl EtherSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

First 4.44 g (33.3 mmol) of aluminium chloride in 150 ml of absolute diethyl ether are added dropwise while stirring at room temperature to a suspension of 7.59 g (200 mmol) of lithium aluminium hydride in 300 ml of absolute diethyl ether. Then 17.32 g (100 mmol) of 3-cyanomethylchroman, dissolved in 200 ml of tetrahydrofuran, are added dropwise within a period of 15 minutes. The reaction mixture is stirred for 16 hours at room temperature and then decomposed with 7.6 ml of water, 7.6 ml of sodium hydroxide solution (15% strength) and 22.8 ml of water. The precipitate formed is filtered off with suction and the filtrate is concentrated by evaporation in vacuo. The oily residue is dissolved in diethyl ether and washed with water. The organic phase is then extracted by shaking with 2N hydrochloric acid. The combined hydrochloric acid extracts are rendered alkaline, while cold, with sodium hydroxide solution (30% strength) and extracted with dichloromethane. The combined organic phases are dried over sodium sulphate and concentrated by evaporation in vacuo. 15.95 g (90%) of 3-(2-aminoethyl)chroman are obtained in the form of a colourless oil. The 3-(2-aminoethyl)chroman hydrochloride produced therefrom using hydrochloric acid in diethyl ether crystallises from methanol/diethyl ether and has a melting point of 244°-245°.

Workup

  1. additionare added dropwise within a period of 15 minutes
  2. customThe precipitate formed
  3. filtrationis filtered off with suction
  4. concentrationthe filtrate is concentrated by evaporation in vacuo
  5. dissolutionThe oily residue is dissolved in diethyl ether
  6. washwashed with water
  7. extractionThe organic phase is then extracted
  8. stirringby shaking with 2N hydrochloric acid
  9. extractionwhile cold, with sodium hydroxide solution (30% strength) and extracted with dichloromethane
  10. dry with materialThe combined organic phases are dried over sodium sulphate
  11. concentrationconcentrated by evaporation in vacuo

Sources & evidence

ORD record
ord-ac061bf8f30f4ba2ad8d3e1afcf3ddf0
Source dataset
uspto-grants-1992_05
Patent number
US05112855

Reaction notes

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