Water → 2-(3-Chloro-4-bromobenzyl)-1,2-dihydro-1-oxophthalazin-4-ylacetic acid

HRID 1413795Notes

Reaction equation

HRID 1413795 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([CH:23]=[CH:24][C:25]=1[Br:26])[CH2:5][N:6]1[N:15]=[C:14]([CH2:16][C:17]([O:19]CC)=[O:18])[C:13]2[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=2)[C:7]1=[O:22].[OH-].[K+].O>C(O)C>[Cl:1][C:2]1[CH:3]=[C:4]([CH:23]=[CH:24][C:25]=1[Br:26])[CH2:5][N:6]1[N:15]=[C:14]([CH2:16][C:17]([OH:19])=[O:18])[C:13]2[C:8](=[CH:9][CH:10]=[CH:11][CH:12]=2)[C:7]1=[O:22]

Participants

5

Reactant 3

HCID 962WaterHCID 14797Potassium HydroxideHCID 20495807Ethyl 2-(3-chloro-4-bromobenzyl)-1,2-dihydro-1-oxophthalazin-4-ylacetate

Product 1

HCID 204958292-(3-Chloro-4-bromobenzyl)-1,2-dihydro-1-oxophthalazin-4-ylacetic acidYield 59.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of ethyl 2-(3-chloro-4-bromobenzyl)-1,2-dihydro-1-oxophthalazin-4-ylacetate (7.0 g.) in ethanol (70 ml.) containing potassium hydroxide (7.0 g.) was heated under reflux for 30 minutes. The solution was then poured into water (250 ml.) and the aqueous solution was extracted with ether (2×150 ml.). The aqueous phase was acidified to pH 2 with concentrated hydrochloric acid. The solid which was thus precipitated was separated, washed with water, dried in vacuo and then recrystallised from a 6:2:3 v/v/v mixture of toluene, propan-2-ol and petrol (60-80) to give 2-(3-chloro-4-bromobenzyl)-1,2-dihydro-1-oxophthalazin-4-ylacetic acid (3.9 g.), m.p. 186° C.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 30 minutes
  3. extractionthe aqueous solution was extracted with ether (2×150 ml.)
  4. customThe solid which was thus precipitated
  5. customwas separated
  6. washwashed with water
  7. customdried in vacuo
  8. customrecrystallised from a 6:2:3 v/v/v mixture of toluene, propan-2-ol and petrol (60-80)

Sources & evidence

ORD record
ord-e76b4b099f36480eaa3960ab222da271
Source dataset
uspto-grants-1981_02
Patent number
US04251528

Reaction notes

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