Ethyl bromoacetate → [4-(1,2-Benzothiazol-3-yl)-2,3-dichlorophenoxy]acetic acid

HRID 1607894Notes

Reaction equation

HRID 1607894 reaction equation
[S:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[C:3]([C:10]2[CH:15]=[CH:14][C:13]([OH:16])=[C:12]([Cl:17])[C:11]=2[Cl:18])=[N:2]1.Br[CH2:20][C:21]([O:23]CC)=[O:22].C([O-])([O-])=O.[K+].[K+].[OH-].[Na+].[Na]>CN(C)C=O>[S:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[C:3]([C:10]2[CH:15]=[CH:14][C:13]([O:16][CH2:20][C:21]([OH:23])=[O:22])=[C:12]([Cl:17])[C:11]=2[Cl:18])=[N:2]1

Participants

7

Reactant 5

HCID 7748Ethyl bromoacetateHCID 11430Potassium CarbonateHCID 14798Sodium HydroxideHCID 5360545SodiumHCID 13596777585893-94-3

Product 1

HCID 14536449[4-(1,2-Benzothiazol-3-yl)-2,3-dichlorophenoxy]acetic acid

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

The phenol product was warmed at 50° for 30 minutes in 100 ml of dimethylformamide containing 2.90 ml of ethyl bromoacetate and 5.5 g of K2CO3. Twenty mililiters (20 ml) of 20% aqueous NaOH was then added to the mixture and warming was continued an additional 30 minutes with vigorous stirring. The product acid which was in the sodium salt formwas filtered off and washed with water, and then with ether. It was then distributed between 2-butanone and 5% HCl. The organic phase was withdrawn, dried and concentrated under reduced pressure. After recrystallization from acetone/H2O, 8.4 g of a pure product (84% from the methoxy compound), m.p. 224°-226° was obtained.

Workup

  1. temperaturewarming
  2. filtrationfiltered off
  3. washwashed with water
  4. customThe organic phase was withdrawn
  5. customdried
  6. concentrationconcentrated under reduced pressure
  7. customAfter recrystallization from acetone/H2O, 8.4 g of a pure product (84% from the methoxy compound), m.p. 224°-226°
  8. customwas obtained

Sources & evidence

ORD record
ord-e80628834e4049d59b8e6d9223316bf5
Source dataset
uspto-grants-1989_09
Patent number
US04868188

Reaction notes

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