N,N,N',N'-Tetramethylethylenediamine → 2-methyl-8H-indeno[2,1-b]thiophen-8-one

HRID 853112Notes

Reaction equation

HRID 853112 reaction equation
[CH3:1][C:2]1[S:3][CH:4]=[C:5]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[CH:6]=1.CN(CCN(C)C)C.[Li]CCCC.CN(C)[C:28](=O)[O:29]CC.[NH4+].[Cl-]>C(OCC)C.CCCCCC>[CH3:1][C:2]1[S:3][C:4]2[C:28](=[O:29])[C:12]3[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=3[C:5]=2[CH:6]=1

Participants

8

Reactant 5

HCID 8037N,N,N',N'-TetramethylethylenediamineHCID 12709Carbamic acid, N,N-dimethyl-, ethyl esterHCID 25517Ammonium ChlorideHCID 114010612-Methyl-4-phenylthiopheneHCID 178418339Butyllithium

Product 1

HCID 112756712-methyl-8H-indeno[2,1-b]thiophen-8-one

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolvent2×HCID 8058HexaneSolvent

Conditions

Temperature
-40 °C

Procedure

A solution of 12.88 g (0.074 mol) of 2-methyl-4-phenylthiophene, 23.4 mL (0.16 mol) of TMEDA in 200 mL of diethyl ether (ether) was treated with 100 mL (0.16 mol) of 1.6M BuLi in hexane under stirring at −40° C. Then the reaction mixture was allowed to warm up to room temperature (r.t.) and was stirred for 3 h (white precipitate forms). The reaction mixture was cooled to −40° C. and treated with 8.76 g (0.075 mol) of ethyl N,N-dimethylcarbamate in 25 mL of ether. Then the reaction mixture was allowed to warm up to r.t. and was stirred overnight. Resulting mixture was treated with 10% aqueous NH4Cl, the organic layer was separated and the organic phase was washed with 10% aqueous solution of NH4Cl and then dried by anhydrous Na2SO4. Solvent was evaporated and the residue was washed with methanol. Yield 6.8 g (46%) of red crystals.

Workup

  1. temperatureto warm up to room temperature (r.t.)
  2. stirringwas stirred for 3 h (white precipitate forms)
  3. temperatureThe reaction mixture was cooled to −40° C.
  4. temperatureto warm up to r.t.
  5. stirringwas stirred overnight
  6. customResulting mixture
  7. customthe organic layer was separated
  8. washthe organic phase was washed with 10% aqueous solution of NH4Cl
  9. dry with materialdried by anhydrous Na2SO4
  10. customSolvent was evaporated
  11. washthe residue was washed with methanol

Sources & evidence

ORD record
ord-158b5e56f52949218843fdf63d27806a
Source dataset
uspto-grants-2007_08
Patent number
US07253292B2

Reaction notes

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