Iodine → 3-Bromo-3,4,5,6-tetrahydro-1-benzazocin-2(1H)-one

HRID 2417841Notes

Reaction equation

HRID 2417841 reaction equation
[NH:1]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[CH2:6][CH2:5][CH2:4][CH2:3][C:2]1=[O:13].P(Cl)(Cl)(Cl)(Cl)Cl.II.[Br:22]Br>C(Cl)(Cl)Cl>[Br:22][CH:3]1[CH2:4][CH2:5][CH2:6][C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=2[NH:1][C:2]1=[O:13]

Participants

6

Reactant 4

HCID 807IodineHCID 24408BromineHCID 24819Phosphorus pentachlorideHCID 124339533,4,5,6-Tetrahydro-1-benzazocin-2(1H)-one

Product 1

HCID 134994413-Bromo-3,4,5,6-tetrahydro-1-benzazocin-2(1H)-one

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

To a solution of 4.7 g of 3,4,5,6-tetrahydro-1-benzazocin-2(1H)-one, J. Chem. Soc. (C), 2176 (1969) in chloroform (75 ml), phosphorus pentachloride (5.9 g) is added in portions, while maintaining the temperature at 0°-5° C. When addition is complete, iodine (60 mg) is added, followed by bromine (4.5 g), which is added dropwise over five minutes. The mixture is then refluxed for 4 hours. The chloroform solution is evaporated and the residue partitioned between ice/water (60 ml) and dichloromethane (100 ml). The organic phase is dried over magnesium sulfate and evaporated under reduced pressure. The crude residue is purified by chromatography on silica gel, eluting with ether/hexane mixtures. Concentration of the appropriate fractions yields 3-bromo-3,4,5,6-tetrahydro-1-benzazocin-2(1H)-one.

Workup

  1. temperaturewhile maintaining the temperature at 0°-5° C
  2. additionWhen addition
  3. additionis added dropwise over five minutes
  4. temperatureThe mixture is then refluxed for 4 hours
  5. customThe chloroform solution is evaporated
  6. customthe residue partitioned between ice/water (60 ml) and dichloromethane (100 ml)
  7. dry with materialThe organic phase is dried over magnesium sulfate
  8. customevaporated under reduced pressure
  9. customThe crude residue is purified by chromatography on silica gel
  10. washeluting with ether/hexane mixtures

Sources & evidence

ORD record
ord-2e2f34dbd3b9469aa303479e6f368c14
Source dataset
uspto-grants-1984_09
Patent number
US04470988

Reaction notes

Loading…