p-Chlorophenethylic alcohol → 1,2,3,3a,8,8a-Hexahydro-alpha-oxo-1,3a,8-trimethyl-5-pyrrolo[2,3-b]indole acetic acid, 4-chlorophenylethyl ester

HRID 258148Notes

Reaction equation

HRID 258148 reaction equation
[O:1]=[C:2]([C:8]1[CH:9]=[C:10]2[C:14](=[CH:15][CH:16]=1)[N:13]([CH3:17])[CH:12]1[N:18]([CH3:21])[CH2:19][CH2:20][C:11]21[CH3:22])[C:3]([O:5][CH2:6][CH3:7])=[O:4].[Cl:23][C:24]1[CH:29]=[CH:28][C:27](CCO)=[CH:26][CH:25]=1>[O-]CC.[Ti+4].[O-]CC.[O-]CC.[O-]CC>[O:1]=[C:2]([C:8]1[CH:9]=[C:10]2[C:14](=[CH:15][CH:16]=1)[N:13]([CH3:17])[CH:12]1[N:18]([CH3:21])[CH2:19][CH2:20][C:11]21[CH3:22])[C:3]([O:5][CH2:6][CH2:7][C:27]1[CH:28]=[CH:29][C:24]([Cl:23])=[CH:25][CH:26]=1)=[O:4]

Participants

4

Procedure

To a chilled (0° C.) solution of 1,2,3,3a,8,8a-hexahydro-α-oxo-1,3a,8-trimethyl-5-pyrrolo[2,3-b]indole acetic acid, ethyl ester (1.18 g) in 4-chlorophenylethyl alcohol (31 ml) was added titanium (IV) ethoxide (0.30 ml) under a nitrogen atmosphere with stirring. The mixture was gently heated without refluxing for 4 hours. The 4-chlorophenylethyl alcohol was removed by distillation under high vacuum and the crude residue was dissolved in dichloromethane (20 ml) and washed successively with two 100 ml portions of saturated ammonium chloride solution, two 100 ml portions of saturated sodium bicarbonate solution and 100 ml of brine. The organic phase was dried (Na2SO4) filtered, and purified using preparative HPLC (silica gel, 3% methanol in dichloromethane as the loading solvent and eluent). The appropriate fractions were combined and the solvent removed under vacuum. Concentration of the appropriate fractions yielded 0.87 g of 1,2,3,3a,8,8a-hexahydro-α-oxo-1,3a,8-trimethyl-5-pyrrolo[2,3-b]indole acetic acid, 4 -chlorophenylethyl ester as an oil.

Workup

  1. temperatureThe mixture was gently heated
  2. temperaturewithout refluxing for 4 hours
  3. customThe 4-chlorophenylethyl alcohol was removed by distillation under high vacuum
  4. dissolutionthe crude residue was dissolved in dichloromethane (20 ml)
  5. washwashed successively with two 100 ml portions of saturated ammonium chloride solution, two 100 ml portions of saturated sodium bicarbonate solution and 100 ml of brine
  6. dry with materialThe organic phase was dried (Na2SO4)
  7. filtrationfiltered
  8. custompurified
  9. customthe solvent removed under vacuum

Sources & evidence

ORD record
ord-5c3816153d044af38db2d746eab79685
Source dataset
uspto-grants-1993_11
Patent number
US05264587

Reaction notes

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