Water → 4-bromo-2H-phthalazin-1-one

HRID 1198933Notes

Reaction equation

HRID 1198933 reaction equation
[C:1]([NH:13][NH2:14])(=O)[C:2]1[C:3](=[CH:8][CH:9]=[CH:10][CH:11]=1)[C:4](NN)=[O:5].P(Br)(Br)(Br)(Br)[Br:16].O>C(Br)(Br)(Br)Br>[Br:16][C:1]1[C:2]2[C:3](=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:4](=[O:5])[NH:14][N:13]=1

Participants

5

Reactant 3

HCID 962WaterHCID 62678Phosphorus pentabromideHCID 11367556Phthalohydrazide

Product 1

HCID 6143104-bromo-2H-phthalazin-1-one

Reagents, catalysts & solvents 1

HCID 11205Carbon tetrabromideSolvent

Procedure

A mixture of phthalhydrazide (3.2 g) and phosphorus pentabromide (19.0 g) was heated with stirring in carbon tetrabromide (50 g) at 125° for 16 hours. The cooled mixture was poured into water (50 cm3) and the product collected by filtration. The solid product was chromatographed on silica (Merck "MK 60.9385" [Trade Mark]) eluting with diethyl ether:dichloromethane, 1:3 by volume. Combination and evaporation of appropriate fractions afforded the title compound, m.p. 268°-271° (1.5 g).

Workup

  1. temperaturewas heated
  2. filtrationthe product collected by filtration
  3. customThe solid product was chromatographed on silica (Merck "MK 60.9385" [Trade Mark])
  4. washeluting with diethyl ether
  5. customCombination and evaporation of appropriate fractions

Sources & evidence

ORD record
ord-b862737d7f5149f48b00d895c9b4d79c
Source dataset
uspto-grants-1990_02
Patent number
US04898872

Reaction notes

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