Indole → 3-Phenylthioindole

HRID 890007Notes

Reaction equation

HRID 890007 reaction equation
[C:1]1([S:7]([CH3:9])=O)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.FC(F)(F)C(OC(=O)C(F)(F)F)=O.[NH:23]1[C:31]2[C:26](=[CH:27][CH:28]=[CH:29][CH:30]=2)C=[CH:24]1.C(N(CC)CC)C>C(Cl)Cl.O>[C:1]1([S:7][C:9]2[C:26]3[C:31](=[CH:30][CH:29]=[CH:28][CH:27]=3)[NH:23][CH:24]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

7

Reactant 4

HCID 798IndoleHCID 8471TriethylamineHCID 9845Trifluoroacetic anhydrideHCID 14516Methyl phenyl sulfoxide

Product 1

HCID 8524893-PhenylthioindoleYield 88%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-78 °C

Procedure

A solution of methyl phenyl sulfoxide (4.0 g, 147 mmol) in CH2Cl2 is cooled to −78° C., treated dropwise with trifluoroacetic anhydride (4.0 mL, 5.99 g, 28.5 mmol), stirred for 30 min at −78° C., treated with a solution of indole (1.82 g, 15.6 mmol) in CH2Cl2, stirred for 30 min at −78° C., treated with triethylamine (20 mL, 145 mmol), stirred for 4 days at ambient temperatures and diluted with water. The phases are separated. The organic phase is dried over MgSO4 and concentrated in vacuo. The resultant residue is chromatographed (1:99 methanol:CH2Cl2) to give the title product as a white solid, 3.08 g (88% yield), mp 149–151° C., characterized by mass spectral and HNMR analyses.

Workup

  1. stirringstirred for 30 min at −78° C.
  2. stirringstirred for 4 days at ambient temperatures
  3. customThe phases are separated
  4. dry with materialThe organic phase is dried over MgSO4
  5. concentrationconcentrated in vacuo
  6. customThe resultant residue is chromatographed (1:99 methanol:CH2Cl2)

Sources & evidence

ORD record
ord-aa38657b0d254727b5ec5de04a98cb6c
Source dataset
uspto-grants-2006_02
Patent number
US06995176B2

Reaction notes

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