Diethyl Ether → cis-4b,5,9b,10-Tetrahydro-4b,9b-dimethyl-8-isopropylindeno[1,2-b]indole

HRID 439858Notes

Reaction equation

HRID 439858 reaction equation
C[Li].[CH3:3][C:4]12[CH2:22][C:21]3[C:16](=[CH:17][CH:18]=[CH:19][CH:20]=3)[C:5]1=[N:6][C:7]1[CH:8]=[CH:9][C:10]([CH:13]([CH3:15])[CH3:14])=[CH:11][C:12]=12.[Cl-].[NH4+].[CH2:25](OCC)C>O1CCCC1>[CH3:25][C@@:5]12[C:16]3[C:21](=[CH:20][CH:19]=[CH:18][CH:17]=3)[CH2:22][C@:4]1([CH3:3])[C:12]1[CH:11]=[C:10]([CH:13]([CH3:15])[CH3:14])[CH:9]=[CH:8][C:7]=1[NH:6]2

Participants

6

Reactant 4

HCID 3283Diethyl EtherHCID 25517Ammonium Chloride2×HCID 150827489b,10-Dihydro-9b-methyl-8-isopropylindeno-[1,2-b]indoleHCID 178418348HCID 178418348, compound

Product 1

HCID 15082750cis-4b,5,9b,10-Tetrahydro-4b,9b-dimethyl-8-isopropylindeno[1,2-b]indole

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

To a solution of methyllithium (1.4M in ether, 14.5 cm3, 12.4 mmol) in dry tetrahydrofuran (20 cm3), at -78° C., under nitrogen, in a flame dried flask, was added dropwise, over 1 hour, a solution of 9b,10-dihydro-9b-methyl-8-isopropylindeno-[1,2-b]indole (1.62 g, 6.20 mmol) in dry tetrahydrofuran (30 cm3). After addition, the mixture was stirred for a further 1/2 hour at -78° C. Saturated ammonium chloride solution (2 cm3) was then added and the mixture allowed to warm to room temperature. The reaction mixture was then portioned between diethyl ether (50 cm3) and saturated ammonium chloride solution (25 cm3), and the layers separated. The aqueous phase was extracted with diethyl ether (2×10 cm3) and the combined organic extracts were washed brine, dried (Na2SO4) and evaporated. The crude material thus obtained was purified by flash chromatography on silica gel eluting with 3-10% ethyl acetate/60°-80° petrol to yield a pale yellow gum. Yield: 0.77 g, 45%. 1H NMR (CDCl3) δ: 7.1-7.3 (4H, m), 6.98 (1H, d, J=1.8 Hz ), 6.82 (1H, dd, J=1.8 Hz and 7.9 Hz ), 6.47 (1H, d, J=7.9 Hz), 3.36 (1H, d, J=15.9 Hz), 3.06 (1H, d, J=15.9 Hz), 2.78 (1H, sept., J=6.8 Hz), 1.45 (3H, s), 1.34 (3H, s), 1.18 (6H, dd, J=1.3 Hz and 6.9 Hz).

Workup

  1. additionwas added dropwise, over 1 hour
  2. additionAfter addition
  3. temperatureto warm to room temperature
  4. customthe layers separated
  5. extractionThe aqueous phase was extracted with diethyl ether (2×10 cm3)
  6. washthe combined organic extracts were washed brine
  7. dry with materialdried (Na2SO4)
  8. customevaporated

Sources & evidence

ORD record
ord-22f1072be7914e468df78075709a3bb9
Source dataset
uspto-grants-1996_05
Patent number
US05516788

Reaction notes

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