diethyl 1-(1-cyanoethyl)-1H-indole-2,6-dicarboxylate → Ethyl 4-methyl-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-7-carboxylate

HRID 1748244Notes

Reaction equation

HRID 1748244 reaction equation
[C:1]([CH:3]([N:5]1[C:13]2[C:8](=[CH:9][CH:10]=[C:11]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH:12]=2)[CH:7]=[C:6]1[C:19]([O:21]CC)=O)[CH3:4])#[N:2]>C(O)C.[Pt]=O>[CH3:4][CH:3]1[N:5]2[C:13]3[CH:12]=[C:11]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH:10]=[CH:9][C:8]=3[CH:7]=[C:6]2[C:19](=[O:21])[NH:2][CH2:1]1

Participants

4

Reactant 1

HCID 67235490diethyl 1-(1-cyanoethyl)-1H-indole-2,6-dicarboxylate

Product 1

HCID 67235749Ethyl 4-methyl-1-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]indole-7-carboxylateYield 95%

Reagents, catalysts & solvents 2

HCID 82844Platinum oxide (PtO)Catalyst2×HCID 702EthanolSolvent2×

Procedure

To a solution of diethyl 1-(1-cyanoethyl)-1H-indole-2,6-dicarboxylate (3.9 g, 12.4 mmol) in ethanol (500 mL) is added platinum oxide (2.0 g, 8.8 mmol). The reaction mixture is then shaken under 50 psi of H2 for 4 h. Additional platinum oxide (700 mg, 3.1 mmol) is added along with more ethanol (10 mL) and the mixture is shaken under 50 psi of H2 for another 16 h. The reaction mixture is filtered through Celite under a flow of N2 and the Celite is rinsed with EtOAc. The filtrates are combined and concentrated to afford the title compound (3.2 g, 95%) which is used in the next step without further purification.

Workup

  1. stirringthe mixture is shaken under 50 psi of H2 for another 16 h
  2. filtrationThe reaction mixture is filtered through Celite under a flow of N2
  3. washthe Celite is rinsed with EtOAc
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-4cb74fb8428f483f98cce4c3002eaae9
Source dataset
uspto-grants-2015_10
Patent number
US09150577B2

Reaction notes

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