Bromine → 7-Chloro-3-methylphthalide

HRID 491003Notes

Reaction equation

HRID 491003 reaction equation
[Cl:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]([CH2:11][CH3:12])[C:3]=1[C:4]([OH:6])=[O:5].BrBr.S([O-])([O-])(=O)=S.[Na+].[Na+]>ClC1C=CC=CC=1>[Cl:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]2[C:3]=1[C:4](=[O:6])[O:5][CH:11]2[CH3:12]

Participants

5

Reactant 3

HCID 24408BromineHCID 24477Sodium ThiosulfateHCID 226137692-Chloro-6-ethylbenzoic acid

Product 1

HCID 112523687-Chloro-3-methylphthalide

Reagents, catalysts & solvents 1

HCID 7964ChlorobenzeneSolvent2×

Conditions

Temperature
90 °C

Procedure

5.00 g (0.027 mol) of 2-chloro-6-ethylbenzoic acid in 120 ml of chlorobenzene are introduced into a reaction vessel and heated to 90° C. 0.1 g of α,α′-azoisobutyronitrile is then added, followed by 5.04 g (0.03154 mol) of bromine in 25 ml of chlorobenzene, which is metered in the course of 10 minutes. The reaction mixture is then stirred for 1 hour at 90° C. to complete the reaction. After the reaction mixture has cooled to 20° C., it is washed with 50 ml of sodium thiosulfate solution (0.1 mol), the organic phase is dried over sodium sulfate and the solvent evaporated off under reduced pressure using a rotary evaporator. The desired target compound is obtained in a yield of 6.1 g and a purity of about 74% (corresponding to 90% of theory).

Workup

  1. customis metered in the course of 10 minutes
  2. customthe reaction
  3. temperatureAfter the reaction mixture has cooled to 20° C.
  4. dry with materialthe organic phase is dried over sodium sulfate
  5. customthe solvent evaporated off under reduced pressure
  6. customa rotary evaporator
  7. customThe desired target compound is obtained in a yield of 6.1 g

Sources & evidence

ORD record
ord-cac880f27b5b474986fb61feefd75f1e
Source dataset
uspto-grants-2009_05
Patent number
US07528266B2

Reaction notes

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