Peracetic Acid → Phthalazine 2-oxide

HRID 986903Notes

Reaction equation

HRID 986903 reaction equation
[CH:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH:4]=[N:3][N:2]=1.C(OO)(=[O:13])C>C(O)(=O)C>[CH:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH:4]=[N:3][N+:2]=1[O-:13]

Participants

4

Reactant 2

HCID 6585Peracetic AcidHCID 9207Phthalazine

Product 1

HCID 87735Phthalazine 2-oxide

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Conditions

Temperature
80 °C

Procedure

Phthalazine (0.40 moles) was dissolved in 200 ml of glacial acetic acid. Under nitrogen, 10 ml portions of a 32% solution of peracetic acid in acetic acid were added until 0.44 mole had been added and then the mixture was heated to 80° C. for 1 hour. The resulting reaction mixture was cooled to room temperature and the acetic acid was removed using a rotary evaporator. The solid residue was suspended/dissolved in 500 ml water and treated with 50 ml of 50% sodium hydroxide and extracted 5 times with 500 ml of dichloromethane. The organic extracts were combined, dried over magnesium sulfate, crystallized from dichloromethane-hexane, and vacuum-dried to yield 50.1 g of phthalazine N-oxide (0.34 mole), mp (DSC)=149° C. GC analysis showed the desired product contained less than 0.5% phthalazine.

Workup

  1. additionhad been added
  2. customThe resulting reaction mixture
  3. temperaturewas cooled to room temperature
  4. customthe acetic acid was removed
  5. customa rotary evaporator
  6. dissolutionThe solid residue was suspended/dissolved in 500 ml water
  7. additiontreated with 50 ml of 50% sodium hydroxide
  8. extractionextracted 5 times with 500 ml of dichloromethane
  9. dry with materialdried over magnesium sulfate
  10. customcrystallized from dichloromethane-hexane
  11. customvacuum-dried

Sources & evidence

ORD record
ord-d7c3ca4d741046ea8006d1a880b59cdd
Source dataset
uspto-grants-2003_10
Patent number
US06630291B1

Reaction notes

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