Trimethyltin chloride → 1-tert-butyl 6-methyl 2-(trimethylstannyl)-1H-indole-1,6-dicarboxylate

HRID 585014Notes

Reaction equation

HRID 585014 reaction equation
C([N-]C(C)C)(C)C.[Li+].[N:9]1([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[C:17]2[C:12](=[CH:13][CH:14]=[C:15]([C:18]([O:20][CH3:21])=[O:19])[CH:16]=2)[CH:11]=[CH:10]1.[CH3:29][Sn:30](Cl)([CH3:32])[CH3:31]>C1COCC1>[CH3:29][Sn:30]([CH3:32])([CH3:31])[C:10]1[N:9]([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[C:17]2[C:12]([CH:11]=1)=[CH:13][CH:14]=[C:15]([C:18]([O:20][CH3:21])=[O:19])[CH:16]=2

Participants

5

Reactant 3

HCID 14016Trimethyltin chlorideHCID 2724682Lithium diisopropylamideHCID 208216591-tert-Butyl 6-methyl 1H-indole-1,6-dicarboxylate

Product 1

HCID 113626351-tert-butyl 6-methyl 2-(trimethylstannyl)-1H-indole-1,6-dicarboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

A solution of lithium diisopropylamide (0.50 M, 72.6 mL, 36.2 mmol, 1.6 equiv) was added via cannula to a solution of 1-tert-butyl 6-methyl 1H-indole-1,6-dicarboxylate (1-5, 6.23 g, 22.6 mmol) in THF (100 mL) at −78° C. The resulting mixture was stirred for 2 hours at −78° C. before a solution of trimethyltin chloride in THF (2.3 M, 19.7 ml, 45.3 mmol, 2.00 equiv) was added. The resulting solution was warmed to 0° C. for 15 minutes, then partitioned between EtOAc (2×150 mL) and aqueous half-saturated NH4Cl solution (200 mL). The combined organics layers were dried over sodium sulfate and concentrated. The residue was purified by flash column chromatography (100% hexanes initially, grading to 20% EtOAc in hexanes) to afford 1-tert-butyl 6-methyl 2-(trimethylstannyl)-1H-indole-1,6-dicarboxylate (1-6) as an orange oil. 1H NMR (300 MHz, CDCl3) δ 8.74 (s, 1H), 7.88 (dd, 1H, J=8.2, 1.8 Hz), 7.53 (d, 1H, J=8.2 Hz), 6.77 (br s, 1H), 3.95 (s, 3H), 1.74 (s, 9H), 0.33 (s, 9H).

Workup

  1. additionwas added
  2. custompartitioned between EtOAc (2×150 mL) and aqueous half-saturated NH4Cl solution (200 mL)
  3. dry with materialThe combined organics layers were dried over sodium sulfate
  4. concentrationconcentrated
  5. customThe residue was purified by flash column chromatography (100% hexanes initially

Sources & evidence

ORD record
ord-23e0efb70e92423aa2624360dca10fb6
Source dataset
uspto-grants-2005_08
Patent number
US06927293B2

Reaction notes

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