Sulfuric Acid → Indole

HRID 1095515Notes

Reaction equation

HRID 1095515 reaction equation
F[C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][C:10]=1OC)[NH:7][CH:6]=[C:5]2CCO.O1C=CCC1.Cl.FC1C=CC(NN)=CC=1OC.S(=O)(=O)(O)O>C(#N)C>[NH:7]1[C:8]2[C:4](=[CH:3][CH:2]=[CH:10][CH:9]=2)[CH:5]=[CH:6]1

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 709342,3-DihydrofuranHCID 18405711HCID 18405711, compoundHCID 66783208HCID 66783208, compound

Product 1

HCID 798Indole

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent2×

Conditions

Temperature
80 °C

Procedure

2-(5-Fluoro-6-methoxy-1H-indol-3-yl)ethanol (Ind-26) A solution of dihydrofuran (242 mg, 3.46 mmol) in acetonitrile (10 ml) was added dropwise to a solution of (4-fluoro-3-methoxyphenyl)hydrazine hydrochloride [1.00 g, 3.46 mmol (based on a purity of the educt of 68%)] in acetonitrile (30 ml) and 4% aqueous sulfuric acid (30 ml) at room temperature. Thereafter, the temperature was increased to 80° C. and the reaction mixture was stirred at this temperature for 2 h and then cooled to room temperature and the solvent was removed i. vac. 5% sodium bicarbonate solution was added to the residue and the mixture was extracted with ethyl acetate (3×50 ml). The combined organic phases were dried with sodium sulfate and concentrated i. vac.

Workup

  1. customat room temperature
  2. temperaturecooled to room temperature
  3. customthe solvent was removed i
  4. addition5% sodium bicarbonate solution was added to the residue
  5. extractionthe mixture was extracted with ethyl acetate (3×50 ml)
  6. dry with materialThe combined organic phases were dried with sodium sulfate
  7. concentrationconcentrated i

Sources & evidence

ORD record
ord-6c3b13980106412284ff77c384d975a9
Source dataset
uspto-grants-2012_03
Patent number
US08138187B2

Reaction notes

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