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
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
Reactant 2
Product 1
Reagents, catalysts & solvents 1
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
- temperatureThe mixture was gently heated
- temperaturewithout refluxing for 4 hours
- customThe 4-chlorophenylethyl alcohol was removed by distillation under high vacuum
- dissolutionthe crude residue was dissolved in dichloromethane (20 ml)
- 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
- dry with materialThe organic phase was dried (Na2SO4)
- filtrationfiltered
- custompurified
- 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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