Isopropanol → Ethyl cis-3,4-dimethyl-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-7-carboxylate

HRID 1748261Notes

Reaction equation

HRID 1748261 reaction equation
[CH3:1][C@H:2]1[C@@H:17]([CH3:18])[N:6]2[C:7]3[CH:8]=[C:9]([C:14]([OH:16])=[O:15])[CH:10]=[CH:11][C:12]=3[CH:13]=[C:5]2[C:4](=[O:19])[NH:3]1.[CH:20](O)(C)[CH3:21]>CCCCCCC>[CH3:1][C@H:2]1[C@@H:17]([CH3:18])[N:6]2[C:7]3[CH:8]=[C:9]([C:14]([O:16][CH2:20][CH3:21])=[O:15])[CH:10]=[CH:11][C:12]=3[CH:13]=[C:5]2[C:4](=[O:19])[NH:3]1.[CH3:1][C@@H:2]1[C@H:17]([CH3:18])[N:6]2[C:7]3[CH:8]=[C:9]([C:14]([O:16][CH2:20][CH3:21])=[O:15])[CH:10]=[CH:11][C:12]=3[CH:13]=[C:5]2[C:4](=[O:19])[NH:3]1

Participants

5

Reactant 2

HCID 3776IsopropanolHCID 67234926(3S,4R)-3,4-Dimethyl-1-oxo-1,2,3,4-tetrahydro-pyrazino[1,2-a]indole-7-carboxylic acid2×

Product 2

HCID 67234919ethyl (3R,4S)-3,4-dimethyl-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-7-carboxylateYield 45%HCID 67235475Ethyl cis-3,4-dimethyl-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-7-carboxylateYield 46%

Reagents, catalysts & solvents 1

HCID 8900HeptaneSolvent

Procedure

Racemic cis-3,4-dimethyl-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-7-carboxylic acid (Intermediate F, 1.9 g, 6.7 mmol) is separated on a preparative chiral column (Chiralpak AD, 5 cm×50 cm, 20 u, Chiral Technologies, West Chester, Pa.) using Gilson preparative HPLC (Mobile Phase: 12% isopropanol in heptane; Flow rate: 100 mL/min) to afford ethyl (3S,4R)-3,4-dimethyl-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-7-carboxylate (870 mg, 46%) and ethyl (3R,4S)-3,4-dimethyl-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-7-carboxylate (852 mg, 45%).

Sources & evidence

ORD record
ord-41ada2b325894882813051d129af0f33
Source dataset
uspto-grants-2015_10
Patent number
US09150577B2

Reaction notes

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