Sodium Hydroxide → 5,6,10,11-Tetrahydro-2-methoxy-8-methylbenzo[g]pyrazino[1,2-a]indole fumarate

HRID 486591Notes

Reaction equation

HRID 486591 reaction equation
[CH3:1][O:2][C:3]1[CH:21]=[CH:20][C:6]2[CH2:7][CH2:8][C:9]3[CH:10]=[CH:11][N:12]([CH2:14][CH2:15][NH:16][C:17](=O)[CH3:18])[C:13]=3[C:5]=2[CH:4]=1.P(Cl)(Cl)(Cl)=O.[OH-].[Na+].[C:29]([OH:36])(=[O:35])/[CH:30]=[CH:31]/[C:32]([OH:34])=[O:33]>C(O)C>[C:29]([OH:36])(=[O:35])/[CH:30]=[CH:31]/[C:32]([OH:34])=[O:33].[CH3:1][O:2][C:3]1[CH:21]=[CH:20][C:6]2[CH2:7][CH2:8][C:9]3[CH:10]=[C:11]4[C:17]([CH3:18])=[N:16][CH2:15][CH2:14][N:12]4[C:13]=3[C:5]=2[CH:4]=1

Participants

6

Reactant 4

HCID 14798Sodium HydroxideHCID 24813Phosphorus oxychlorideHCID 444972Fumaric AcidHCID 19036540N-[2-(4,5-dihydro-8-methoxy-1H-benz[g]indol-1-yl)ethyl]-acetamide

Product 1

HCID 190953875,6,10,11-Tetrahydro-2-methoxy-8-methylbenzo[g]pyrazino[1,2-a]indole fumarateYield 84%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
50 °C

Procedure

N-[2-(4,5-Dihydro-8-methoxy-1H-benzo[g]indol-1-yl)-ethyl]acetamide (4.7 g) was treated with 15 ml of phosphorus oxychloride under argon and the mixture was stirred at 50° C. for 30 minutes. The cooled mixture was added to 2000 g of ice-water and treated with 200 ml of 28% sodium hydroxide solution. The mixture was extracted once with 300 ml of methylene chloride and twice with 100 ml of methylene chloride each time, the organic phases were combined, dried with MgSO4 and freed from solvent. 4.2 g of residue were chromatographed on 250 g of aluminium oxide (neutral, III) with methylene chloride as the eluent. 3.8 g of crude product were dissolved in a 20-fold amount of hot ethanol and treated while hot with 1.1 equivalents of a saturated solution of fumaric acid in ethanol. There were obtained 4.7 g (84%) of 5,6,10,11-tetrahydro-2-methoxy-8-methylbenzo[g]pyrazino[1,2-a]indole fumarate (1:1); m.pt.: 175°-177° C. (dec.).

Workup

  1. extractionThe mixture was extracted once with 300 ml of methylene chloride and twice with 100 ml of methylene chloride each time
  2. dry with materialdried with MgSO4
  3. custom4.2 g of residue were chromatographed on 250 g of aluminium oxide (neutral, III) with methylene chloride as the eluent
  4. dissolution3.8 g of crude product were dissolved in a 20-fold amount of hot ethanol

Sources & evidence

ORD record
ord-d7d5b841e9874ecd910cd517555c36b5
Source dataset
uspto-grants-1994_03
Patent number
US05292732

Reaction notes

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