Acetic Anhydride → HCID 11770291, compound

HRID 917792Notes

Reaction equation

HRID 917792 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[C:5](OC(=O)C)(=[O:7])[CH3:6].[CH2:12]([O:14][C:15]([C:17]1[NH:18][C:19]2[C:24]([CH:25]=1)=[CH:23][CH:22]=[CH:21][CH:20]=2)=[O:16])[CH3:13]>ClC(Cl)C>[CH2:12]([O:14][C:15]([C:17]1[NH:18][C:19]2[C:24]([C:25]=1[C:5](=[O:7])[CH3:6])=[CH:23][CH:22]=[CH:21][CH:20]=2)=[O:16])[CH3:13].[CH2:12]([O:14][C:15]([C:17]1[NH:18][C:19]2[C:24]([CH:25]=1)=[CH:23][C:22]([C:5](=[O:7])[CH3:6])=[CH:21][CH:20]=2)=[O:16])[CH3:13]

Participants

6

Reactant 3

HCID 7918Acetic AnhydrideHCID 73125Ethyl indole-2-carboxylateHCID 6451240Aluminum(III) Chloride

Product 2

HCID 4162576HCID 4162576, compoundYield 13%HCID 11770291HCID 11770291, compoundYield 52%

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent2×

Conditions

Temperature
40 °C

Procedure

Aluminum chloride (7.75 g, 0.058 mol) was suspended in 200 ml of anhydrous dichloroethane at room temp. followed by a slow addition of acetic anhydride (2.74 mL, 0.03 mol). The mixture was stirred at room temp for 10 minutes after which, 1H-indole-2-carboxylic acid ethyl ester (1b, 5.0 g, 0.0264 mol) was added as a solution in 15 mL of dichloroethane. The reaction mixture was stirred under nitrogen at 40° C. for 10 h. The reaction was quenched with an ice-water mixture and the organic layer was washed with water (3×). The organic phase was dried over anh. Na2SO4, filtered and concentrated in vacuo. Chromatography on SiO2 (4% Ethyl acetate/96% CH2Cl2) provided 3.2 g of 3-acetyl-1H-indole-2-carboxylic acid ethyl ester 2b (52%) and 770 mg of 5-acetyl-1H-indole-2-carboxylic acid ethyl ester 3b (13%).

Workup

  1. customThe reaction was quenched with an ice-water mixture
  2. washthe organic layer was washed with water (3×)
  3. dry with materialThe organic phase was dried over anh. Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-9040330d5f974d39a7e2ea5b10271dbe
Source dataset
uspto-grants-2007_09
Patent number
US07273885B2

Reaction notes

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