Sodium Chloride → Indoxyl

HRID 967697

Reaction equation

HRID 967697 reaction equation
CC([N:4]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:6]([O:13]C(C)=O)=[CH:5]1)=O.[OH-].[Na+].O.C(O)(=O)CC(CC(O)=O)(C(O)=O)O.[Na+].[Cl-]>O>[OH:13][C:6]1[C:7]2[C:12](=[CH:11][CH:10]=[CH:9][CH:8]=2)[NH:4][CH:5]=1

Participants

6

Reactant 4

HCID 5234Sodium ChlorideHCID 14798Sodium HydroxideHCID 222302-Hydroxy-1,2,3-propanetricarboxylic acid hydrate (1:1)HCID 5836021-Acetyl-1H-indol-3-yl acetate

Product 1

HCID 50591IndoxylYield 80.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
85 °C

Procedure

Indoxyl 1,3-diacetate (Sigma Chemical Co., St. Louis, Mo.) (10.0 g; 46.05 mmole) was suspended with stirring in thoroughly deoxygenated H2O (200 mL), maintained under an inert gas atmosphere. NaOH (16 g) was added at once and the reaction mixture was heated at ca. 85° C. for 15 min. The reaction was cooled in an ice/salt bath to <5° C., then dropwise treated with a thoroughly deoxygenated solution of citric acid monohydrate (30.63 g) in H2O (30 mL) at a rate that kept the reaction temperature <5° C. NaCl (30 g) was then added and the reaction stirred in the cold for 1 h. The greenish yellow solid product was collected by filtration with suction, washed with a minimum amount of deoxygenated, ice-cold aq 0.5 N citric acid and dried in vacuo overnight to give 3-hydroxyindole (4.94 g; 80%). This product was used without further purification.

Workup

  1. temperaturemaintained under an inert gas atmosphere
  2. temperatureThe reaction was cooled in an ice/salt bath to <5° C.
  3. customthe reaction temperature <5° C
  4. filtrationThe greenish yellow solid product was collected by filtration with suction
  5. washwashed with a minimum amount
  6. customof deoxygenated
  7. dry with materialice-cold aq 0.5 N citric acid and dried in vacuo overnight

Sources & evidence

ORD record
ord-426312bb4b374230ae8214691fffec75
Source dataset
uspto-grants-2005_10
Patent number
US06955921B2

Linked notes

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