Boron tribromide → (3aS-cis)-1,2,3,3a,8,8a-hexahydro-1-(2-phenylethyl)-3a, 8-dimethylpyrrolo[2,3-b]indol-5-ol

HRID 414183Notes

Reaction equation

HRID 414183 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]2[C:9](=[CH:10][CH:11]=1)[N:8]([CH3:12])[C@H:7]1[N:13]([CH2:16][CH2:17][C:18]3[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=3)[CH2:14][CH2:15][C@@:6]21[CH3:24].B(Br)(Br)Br>C(Cl)(Cl)Cl>[C:18]1([CH2:17][CH2:16][N:13]2[C@@H:7]3[N:8]([CH3:12])[C:9]4[C:5]([C@:6]3([CH3:24])[CH2:15][CH2:14]2)=[CH:4][C:3]([OH:2])=[CH:11][CH:10]=4)[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 57011492(3aS-cis)-1,2,3,3a,8,8a-hexahydro-5-methoxy-1-(2-phenylethyl)-3a,8-dimethylpyrrolo[2,3-b]indole

Product 1

HCID 14349822(3aS-cis)-1,2,3,3a,8,8a-hexahydro-1-(2-phenylethyl)-3a, 8-dimethylpyrrolo[2,3-b]indol-5-ol

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

To a stirred solution under nitrogen of 3.22 g of (3aS-cis)-1,2,3,3a,8,8a-hexahydro-5-methoxy-1-(2-phenylethyl)-3a,8-dimethylpyrrolo[2,3-b]indole in 50 ml of degassed chloroform is added dropwise at 0° C. a solution of 10.1 g of boron tribromide in 50 ml of degassed chloroform. The mixture is stirred for about 3 days at room temperature, cooled to 0° C. and cautiously quenched by the dropwise addition of water. The mixture is stirred vigorously for 0.5 hour, and a sufficient volume of saturated aqueous sodium bicarbonate solution is added to make the system just basic to a pH paper. The organic phase is separated, dried over anhydrous sodium sulfate and concentrated. The residue is Kugelrohr distilled at 0.1 mm Hg at an oven temperature of 160°-200° to provide pure (3aS-cis)-1,2,3,3a,8,8a-hexahydro-1-(2-phenylethyl)-3a,8-dimethylpyrrolo[2,3-b]indol-5-ol.

Workup

  1. temperaturecooled to 0° C.
  2. customcautiously quenched by the dropwise addition of water
  3. stirringThe mixture is stirred vigorously for 0.5 hour
  4. additiona sufficient volume of saturated aqueous sodium bicarbonate solution is added
  5. customThe organic phase is separated
  6. dry with materialdried over anhydrous sodium sulfate
  7. concentrationconcentrated
  8. distillationdistilled at 0.1 mm Hg at an oven temperature of 160°-200°

Sources & evidence

ORD record
ord-a212e727fe0f42a0b9c913522ba6521c
Source dataset
uspto-grants-1988_12
Patent number
US04791107

Reaction notes

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