Triethylamine → 3,4-Dihydro-4-oxo-1-phthalazinecarboxaldehyde

HRID 2119303Notes

Reaction equation

HRID 2119303 reaction equation
[OH:1][CH2:2][C:3]1[C:12]2[C:7](=[CH:8][CH:9]=[CH:10][CH:11]=2)[C:6](=[O:13])[NH:5][N:4]=1.C(N(CC)CC)C.C([O-])([O-])=O.[Na+].[Na+].CCOC(C)=O>CS(C)=O>[C:6]1(=[O:13])[C:7]2[C:12](=[CH:11][CH:10]=[CH:9][CH:8]=2)[C:3]([CH:2]=[O:1])=[N:4][NH:5]1

Participants

6

Reactant 4

HCID 8471TriethylamineHCID 8857Ethyl AcetateHCID 10340Sodium CarbonateHCID 126498924-(Hydroxymethyl)phthalazin-1(2H)-one

Product 1

HCID 157289693,4-Dihydro-4-oxo-1-phthalazinecarboxaldehyde

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent2×

Procedure

Under N2 atmosphere, 50 g (284 mmol) 4-hydroxymethylphthalazin-1(2H)-one is dissolved in 900 ml DMSO and 119 ml (851 mmol) triethylamine. A solution of 90.3 g (567 mmol) sulfur trioxide pyridine complex in 733 ml DMSO is added and the mixture stirred for about 2 h. After the reaction is completed (TLC control), the mixture is poured onto a mixture of 2 l 5% Na2CO3 solution with 2 kg ice and 5 l EtOAc and then stirred. The aqueous phase of the resulting suspension is separated off and twice extracted with 2 l EtOAc. The first organic phase comprises crystalline product, this is filtered off and washed with water and EtOAc. The organic phase is separated off from the filtrate and, together with the second and third organic phase, washed with water and brine, dried (Na2SO4) and evaporated. The evaporation residue is combined with the above crystalline product, stirred in EtOAc, and hexane added before being filtered. This yields the title compound; m.p. 262-265° C.; 1H-NMR (DMSO-d6) 9.82 (s, HCO), 8.88 (d, 1H), 8.27 (d, 1H), 7.95 (m, 2H); FAB-MS (M+H)+=175, (M+H+MeOH)+=207.

Workup

  1. stirringstirred
  2. customThe aqueous phase of the resulting suspension is separated off
  3. extractiontwice extracted with 2 l EtOAc
  4. filtrationthis is filtered off
  5. washwashed with water and EtOAc
  6. customThe organic phase is separated off from the filtrate
  7. washtogether with the second and third organic phase, washed with water and brine
  8. dry with materialdried (Na2SO4)
  9. customevaporated
  10. stirringstirred in EtOAc
  11. additionhexane added
  12. filtrationbefore being filtered

Sources & evidence

ORD record
ord-b9f4ffcf82354239b18bee21784e9979
Source dataset
uspto-grants-2004_02
Patent number
US06686347B2

Reaction notes

Loading…