Boron tribromide → [1R*,8S*,9aR*]1-Amino-5,6-dihydroxy-8-phenyl-2,3,7,8,9,9a-hexahydrophenalene hydrobromide

HRID 1089030Notes

Reaction equation

HRID 1089030 reaction equation
[NH2:1][C@H:2]1[C@H:13]2[C:14]3[C:5](=[CH:6][C:7]([O:23]C)=[C:8]([O:21]C)[C:9]=3[CH2:10][C@@H:11]([C:15]3[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=3)[CH2:12]2)[CH2:4][CH2:3]1.B(Br)(Br)[Br:26]>C(Cl)Cl>[BrH:26].[NH2:1][C@H:2]1[C@H:13]2[C:14]3[C:5](=[CH:6][C:7]([OH:23])=[C:8]([OH:21])[C:9]=3[CH2:10][C@@H:11]([C:15]3[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=3)[CH2:12]2)[CH2:4][CH2:3]1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 18641659HCID 18641659, compound

Product 1

HCID 18641657[1R*,8S*,9aR*]1-Amino-5,6-dihydroxy-8-phenyl-2,3,7,8,9,9a-hexahydrophenalene hydrobromide

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of 0.4 g (1.2 mmol) of [1R,8S,9aR]-1-amino-5,6-dimethoxy-2,3,7,8,9,9a-hexahydro-8 phenyl-phenalene, from Step 7, in 9 mL of methylene chloride was treated with 4.4 mL of a 1M solution of boron tribromide in methylene chloride (4.4 mmol), added dropwise at -78° C. The reaction mixture was warmed to ambient temperature for 1 h and recooled to 78° C. and quenched with 5 mL of methanol. The reaction mixture was allowed to warm to ambient temperature and stirred at ambient temperature for 1 h. The solvent was removed in vacuo. Methanol (5 mL) was added and the solution was concentrated to remove methyl borate by azeotropic distillation. The title compound was obtained after recrystallization from ethanol/diethyl ether as a white solid.

Workup

  1. additionadded dropwise at -78° C
  2. customrecooled to 78° C.
  3. customquenched with 5 mL of methanol
  4. temperatureto warm to ambient temperature
  5. customThe solvent was removed in vacuo
  6. additionMethanol (5 mL) was added
  7. concentrationthe solution was concentrated
  8. customto remove methyl borate
  9. distillationby azeotropic distillation

Sources & evidence

ORD record
ord-2a819bf828d043639af7a4ef1e68f8a8
Source dataset
uspto-grants-1990_10
Patent number
US04963568

Reaction notes

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