Ethyl Acetate → 5-(Benzoxycarbonylamino)-1,2,3,3a,8,8a-hexahydro-1,3a,8-trimethylpyrrolo-[2,3-b]indole
Reaction equation
[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH3:13])[CH:8]1[N:14]([CH3:17])[CH2:15][CH2:16][C:7]21[CH3:18])([O-])=O.[C:19]([O:22][CH2:23][CH3:24])(=[O:21])C>O=[Pt]=O>[CH2:23]([O:22][C:19]([NH:1][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH3:13])[CH:8]1[N:14]([CH3:17])[CH2:15][CH2:16][C:7]21[CH3:18])=[O:21])[C:24]1[CH:6]=[CH:5][CH:4]=[CH:12][CH:11]=1Participants
Conditions
- Temperature
- 0 °C
Procedure
1,2,3,3a,8,8a-Hexahydro-5-nitro-1,3a,8-trimethylpyrrolo[2,3-b]indole (2.2 g) was dissolved in ethyl acetate (100 ml) and hydrogenated in a Parr apparatus at 45 psi using PtO2 (220 mg) as a catalyst. The reduction was complete within 2 hours. The reduction mixture was filtered directly into a nitrogen flushed flask. 4-Dimethylaminopyridine (0.100 g) and triethylamine (0.9 g) were added, the mixture was cooled to 0° C. and a solution of benzylchloroformate (1.5 g) in ethyl acetate (100 ml) was added over a period of 1.5 hours. The mixture was washed with water (2×100 ml), dried (Na2SO4), concentrated and purified by flash chromatography on silica gel (eluting with 15% MeOH/EtOAc). The pure fractions were concentrated to give 5-(benzoxycarbonylamino)-1,2,3,3a,8,8a-hexahydro-1,3a,8-trimethylpyrrolo-[2,3-b]indole (1.2 g).
Workup
- filtrationThe reduction mixture was filtered directly into a nitrogen flushed flask
- addition4-Dimethylaminopyridine (0.100 g) and triethylamine (0.9 g) were added
- additiona solution of benzylchloroformate (1.5 g) in ethyl acetate (100 ml) was added over a period of 1.5 hours
- washThe mixture was washed with water (2×100 ml)
- dry with materialdried (Na2SO4)
- concentrationconcentrated
- custompurified by flash chromatography on silica gel (eluting with 15% MeOH/EtOAc)
- concentrationThe pure fractions were concentrated
Sources & evidence
- ORD record
- ord-e94cb55401ab46f29e55aa4fba61e753
- Source dataset
- uspto-grants-1992_02
- Patent number
- US05091541
Reaction notes
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