Ammonia → Methyl 4-methoxy-2,3-dihydro-1H-indole-2-carboxylate

HRID 2375764Notes

Reaction equation

HRID 2375764 reaction equation
[Mg].[CH3:2][O:3][C:4]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:5]=1[CH:6]=[C:7]([C:13]([OH:15])=[O:14])[NH:8]2.Cl.N.[CH3:18]O>>[CH3:18][O:14][C:13]([CH:7]1[CH2:6][C:5]2[C:9](=[CH:10][CH:11]=[CH:12][C:4]=2[O:3][CH3:2])[NH:8]1)=[O:15]

Participants

6

Reactant 5

HCID 222AmmoniaHCID 313Hydrochloric AcidHCID 887MethanolHCID 9072484-Methoxy-1H-indole-2-carboxylic acidHCID 5462224Magnesium

Product 1

HCID 22451269Methyl 4-methoxy-2,3-dihydro-1H-indole-2-carboxylateYield 64%

Conditions

Temperature
110 °C

Procedure

119 mg (4.90 mmol) of magnesium turnings are added to a solution of 500 mg (2.44 mmol) of 4-methoxy-1H-indole-2-carboxylic acid in 10 ml of methanol. The mixture is stirred for 3 hours in a bath at 110° C. and then for 1 hour at room temperature. 20 ml of hydrochloric acid are added at 0° C. and the mixture is stirred for one hour. 3 N ammonia solution is then added to pH 10 and the mixture is extracted with 3 times 50 ml of ethyl acetate. The organic phases are dried over magnesium sulfate, filtered and concentrated under reduced pressure. The evaporation residue is purified by chromatography on a silica column using a dichloromethane/ethyl acetate mixture (98/5, then 95/5; v/v) as the eluent to give the expected product in the form of a brown oil with a yield of 64%.

Workup

  1. waitfor 1 hour at room temperature
  2. stirringthe mixture is stirred for one hour
  3. extractionthe mixture is extracted with 3 times 50 ml of ethyl acetate
  4. dry with materialThe organic phases are dried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe evaporation residue is purified by chromatography on a silica column

Sources & evidence

ORD record
ord-e60a9ff312514d9fb42e07561a9f64af
Source dataset
uspto-grants-2008_12
Patent number
US07465811B2

Reaction notes

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