Phosphorus pentachloride → 2-bromo-6-chlorophenanthridine

HRID 1618451Notes

Reaction equation

HRID 1618451 reaction equation
[Br:1][CH:2]1[CH:15]=[CH:14][C:13]2[C:4](=[C:5]3[C:10](=[CH:11][N:12]=2)[CH:9]=[CH:8][CH:7]=[CH:6]3)[C:3]1=O.P(Cl)(Cl)(Cl)(Cl)[Cl:18]>O=P(Cl)(Cl)Cl>[Br:1][C:2]1[CH:15]=[CH:14][C:13]2[C:4](=[C:5]3[C:10](=[C:11]([Cl:18])[N:12]=2)[CH:9]=[CH:8][CH:7]=[CH:6]3)[CH:3]=1

Participants

4

Reactant 2

HCID 24819Phosphorus pentachlorideHCID 66813770HCID 66813770, compound

Product 1

HCID 2826002-bromo-6-chlorophenanthridineYield 78.6%

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Conditions

Temperature
93 °C

Procedure

36.7 g (139 mmol) 2-bromophenanthridinone and 30.7 g (147 mmol) PCl5 were added to a 1 L multi-neck flask (equipped with stir arm, condenser, and base trap) along with 350 mL POCl3 and heated at 93° C. for 16 hours (note: evolution of HCl gas was predominant—destroyed by base trap). Afterwards, the mixture was assayed to determine complete consumption of 2-bromophenanthridinone. A dean stark trap was connected to the flask to remove the solvent by 1/2 volume. Subsequently, equal volumes of toluene were added and distilled off to remove majority of POCl3. After the third addition of toluene, the volume was reduced to 300 mL's and the remainder of the solvent removed via rotary evaporation. The solids were then recrystallized from toluene and dried to give 30.8 g (78.6% yield, 98% assay) 2-bromo-6-chlorophenanthridine as off white solids (GC-MS confirmed).

Workup

  1. custom(note: evolution of HCl gas was predominant—destroyed by base trap)
  2. customconsumption of 2-bromophenanthridinone
  3. customA dean stark trap was connected to the flask
  4. customto remove the solvent by 1/2 volume
  5. additionSubsequently, equal volumes of toluene were added
  6. distillationdistilled off
  7. customto remove majority of POCl3
  8. additionAfter the third addition of toluene
  9. customthe remainder of the solvent removed via rotary evaporation
  10. customThe solids were then recrystallized from toluene
  11. customdried

Sources & evidence

ORD record
ord-f632911192d64163b6fb0370fe200476
Source dataset
uspto-grants-2014_07
Patent number
US08766529B2

Reaction notes

Loading…