3,4-dihydro-2H-pyran → 2-(3-Bromopropoxy)tetrahydro-2H-pyran

HRID 440191Notes

Reaction equation

HRID 440191 reaction equation
[Br:1][CH2:2][CH2:3][CH2:4][OH:5].[O:6]1[CH:11]=[CH:10][CH2:9][CH2:8][CH2:7]1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>ClCCl>[Br:1][CH2:2][CH2:3][CH2:4][O:5][CH:7]1[CH2:8][CH2:9][CH2:10][CH2:11][O:6]1

Participants

5

Reactant 3

HCID 80803,4-dihydro-2H-pyranHCID 123083-Bromo-1-propanolHCID 521998p-Toluenesulfonic acid monohydrate

Product 1

HCID 27779882-(3-Bromopropoxy)tetrahydro-2H-pyranYield 65%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

13.9 g (0.1 mol) of 3-bromopropan-1-ol are mixed with 400 ml of dry dichloromethane and 45.7 ml (0.5 mol) of dihydropyran are added. While stirring and if needed cooling in an ice bath 190 mg (1 mmol) of p-toluenesulfonic acid monohydrate are added in such a way that the temperature of the reaction solution does not exceed 25° C. Subsequently the reaction mixture is left for 2 hours at room temperature and extracted with half-saturated aqueous sodium hydrogen carbonate solution, the dichloromethane phase is washed twice with water, dried with magnesium sulfate and filtered to remove the drying agent and the solvent is distilled off in vacuo. The remaining oil is fractionally distilled in vacuo via a 20 cm Vigreux column. 14.2-16.4 g (65-75%) of colorless oil are obtained, which boils at from 60° to 65° C. (0.5-1 mbar).

Workup

  1. additionare added
  2. additionare added in such a way that the temperature of the reaction solution
  3. customdoes not exceed 25° C
  4. extractionextracted with half-saturated aqueous sodium hydrogen carbonate solution
  5. washthe dichloromethane phase is washed twice with water
  6. dry with materialdried with magnesium sulfate
  7. filtrationfiltered
  8. customto remove the drying agent
  9. distillationthe solvent is distilled off in vacuo
  10. distillationThe remaining oil is fractionally distilled in vacuo via a 20 cm Vigreux column

Sources & evidence

ORD record
ord-d9e60a8869034f67a6e1e37ebd582187
Source dataset
uspto-grants-1996_05
Patent number
US05517350

Reaction notes

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