Trifluoroacetic acid → rac-cis-1,3,3a,4,5,9b-hexahydro-6-methoxy-2H-benzo[e]indol-2-one

HRID 1109238Notes

Reaction equation

HRID 1109238 reaction equation
[CH3:1][O:2][C:3]1[C:15]2[CH2:14][CH2:13][C:12]3[NH:11][C:10](=[O:16])[CH2:9][C:8]=3[C:7]=2[CH:6]=[CH:5][CH:4]=1.C([SiH](CC)CC)C.FC(F)(F)C(O)=O.[OH-].[Na+]>C(Cl)Cl.O>[CH3:1][O:2][C:3]1[C:15]2[CH2:14][CH2:13][C@H:12]3[C@H:8]([CH2:9][C:10](=[O:16])[NH:11]3)[C:7]=2[CH:6]=[CH:5][CH:4]=1

Participants

7

Reactant 4

HCID 6422Trifluoroacetic acidHCID 12052TriethylsilaneHCID 14798Sodium HydroxideHCID 190214751,3,4,5-tetrahydro-6-methoxy-2H-benzo[e]indol-2-one

Product 1

HCID 131718423rac-cis-1,3,3a,4,5,9b-hexahydro-6-methoxy-2H-benzo[e]indol-2-oneYield 81%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

A suspension of 150 g (0.7 mol) of 1,3,4,5-tetrahydro-6-methoxy-2H-benzo[e]indol-2-one in 1.5 l of methylene chloride was treated with 333 ml (2.1 mol) of triethylsilane and then slowly dropwise at 0° and while stirring with 240 ml of trifluoroacetic acid. After stirring for three hours 400 ml of 20% sodium hydroxide solution were added slowly while cooling until a pH of 14 had been reached. Subsequently, the mixture was poured into water and extracted with methylene chloride. The organic phase was washed with sodium chloride solution, dried with sodium sulphate, filtered and evaporated. The residue was treated with 500 ml of ether, whereupon the solid was filtered off and dried at 50°/20 Torr. There were obtained 123 g (81%) of rac-cis-1,3,3a,4,5,9b-hexahydro-6-methoxy-2H-benzo[e]indol-2-one with m.p. 192°-194°. The material showed a Rf value of 0.14 in a thin-layer chromatogram (silica gel, ethyl acetate).

Workup

  1. additionwere added slowly
  2. temperaturewhile cooling until a pH of 14
  3. extractionextracted with methylene chloride
  4. washThe organic phase was washed with sodium chloride solution
  5. dry with materialdried with sodium sulphate
  6. filtrationfiltered
  7. customevaporated
  8. additionThe residue was treated with 500 ml of ether, whereupon the solid
  9. filtrationwas filtered off
  10. customdried at 50°/20 Torr

Sources & evidence

ORD record
ord-1b4582b74b5d4459bb696738e23ff834
Source dataset
uspto-grants-1994_06
Patent number
US05318967

Reaction notes

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