Sulfuric Acid → 2,3-Dihydro-1H-indole-7-carboxylic acid

HRID 6365Notes

Reaction equation

HRID 6365 reaction equation
[C:1]([C:3]1[CH:4]=[CH:5][CH:6]=[C:7]2[C:11]=1[NH:10][CH2:9][CH2:8]2)#N.[OH-:12].[Na+].S(=O)(=O)(O)[OH:15]>>[NH:10]1[C:11]2[C:7](=[CH:6][CH:5]=[CH:4][C:3]=2[C:1]([OH:15])=[O:12])[CH2:8][CH2:9]1

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 41880472,3-dihydro-1H-indole-7-carbonitrile

Product 1

HCID 127011472,3-Dihydro-1H-indole-7-carboxylic acid

Conditions

Temperature
5 °C

Procedure

A mixture of 7-cyanoindoline (4.32 g) and 50% aqueous sulfuric acid (40 ml) was stirred at 110°-120° C. for 5.5 hours, cooled to 5° C. and adjusted to pH 7-8 with 24% aqueous sodium hydroxide. The mixture was washed with ethyl acetate and the aqueous layer was adjusted to pH 2.5-3.0 with 6N hydrochloric acid. The precipitates were collected by filtration to give indoline-7-carboxylic acid (3.25 g).

Workup

  1. washThe mixture was washed with ethyl acetate
  2. filtrationThe precipitates were collected by filtration

Sources & evidence

ORD record
ord-e8a77560b32d4c18a9b1ab844404ff19
Source dataset
uspto-grants-1993_09
Patent number
US05248679

Reaction notes

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