Chlorotrimethylsilane → HCID 18932641, compound

HRID 1452393Notes

Reaction equation

HRID 1452393 reaction equation
[CH3:1][O:2][C:3]1[C:12]2[CH2:11][CH:10]([C:13]([CH3:15])=[O:14])[O:9][CH2:8][C:7]=2[C:6]([O:16][CH3:17])=[CH:5][CH:4]=1.C[Si](Cl)(C)C.C([N-]C(C)C)(C)C.[Li+].C(NC(C)C)(C)C.C([Li])CCC.[Br:43]NC(=O)CCC(N)=O.C(=O)(O)[O-].[Na+]>O1CCCC1>[CH3:1][O:2][C:3]1[C:12]2[CH2:11][CH:10]([C:13]([CH2:15][Br:43])=[O:14])[O:9][CH2:8][C:7]=2[C:6]([O:16][CH3:17])=[CH:5][CH:4]=1

Participants

9

Reactant 7

HCID 6397ChlorotrimethylsilaneHCID 7912DiisopropylamineHCID 516892Sodium BicarbonateHCID 2724682Lithium diisopropylamideHCID 9834204N-BromosuccinamideHCID 10966498HCID 10966498, compoundHCID 178418339Butyllithium

Product 1

HCID 18932641HCID 18932641, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Conditions

Temperature
0 °C

Procedure

To a stirred solution of methyl (5,8-dimethoxy-3,4-dihydrobenzo[2,3-c] pyran-3-yl) ketone (1.905 g, 8.04 mmol) and trimethylsilyl chloride (1.530 μl, 12.0 mmol) in tetrahydrofuran (48 ml) under nitrogen, at -78° C., was slowly added lithium diisopropyl amide (diisopropyl amine 10.71 mmol, n-butyl lithium 4.26 ml of a 2.5M solution in tetrahydrofuran, and 6.0 ml of tetrahydrofuran). After stirring for 10 minutes the temperature was raised to 0° C., and stirring was continued for 10 more minutes. Solvent was removed and the crude product was dissolved in 48 ml of tetrahydrofuran, N-bromosuccinamide (1,716 mg, 9.66 mmol) was added slowly to the solution. After 10 minutes, the reaction system was worked up with saturated aqueous sodium bicarbonate and washed with brine. The titled compound was obtained following flash chromatography (hexanes:ethyl acetate, 9:1) of the crude product. 1H NMR (benzene-d6, 250 MHz) -- : 2.68 (dd,1H,HCHa), 3.16 (dd,1H,HCHe), 3.28 (s,3H,OCH3), 3.32 (s,3H,OCH3), 3.73 (dd,1H,J=4.0,11.8 Hz,CH), 3.81 (dd,2H,CH2Br), 4.51 (d,1H, J=15.8 Hz, HCHaO), 5.05 (d,1H,J=15.8 Hz,HCHeO), 6.335 (dd,2H,ArH),

Workup

  1. customat -78° C.
  2. stirringstirring
  3. customSolvent was removed
  4. dissolutionthe crude product was dissolved in 48 ml of tetrahydrofuran
  5. waitAfter 10 minutes
  6. washwashed with brine

Sources & evidence

ORD record
ord-8a6017d024f54168ab2d77987af78ba6
Source dataset
uspto-grants-1997_02
Patent number
US05606037

Reaction notes

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