Sulfamic Acid → Antipyric acid

HRID 1853091Notes

Reaction equation

HRID 1853091 reaction equation
[CH3:1][N:2]1[C:6]([CH3:7])=[C:5]([CH:8]=[O:9])[C:4](=[O:10])[N:3]1[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.S(=O)(=O)([OH:19])N.Cl([O-])=O.[Na+].[OH-].[Na+]>O1CCCC1.O>[CH3:1][N:2]1[C:6]([CH3:7])=[C:5]([C:8]([OH:19])=[O:9])[C:4](=[O:10])[N:3]1[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1

Participants

7

Reactant 4

HCID 5987Sulfamic AcidHCID 14798Sodium HydroxideHCID 703712,3-Dihydro-1,5-dimethyl-3-oxo-2-phenyl-1H-pyrazole-4-carbaldehydeHCID 23668197Sodium Chlorite

Product 1

HCID 246564Antipyric acid

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred solution of the commercially available 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carbaldehyde (CAS No. 950-81-2) (51.6 g) in tetrahydrofuran (THF) (1 L) at 0° C. was added a solution of sulfamic acid (48.5 g) in water (640 mL). A solution of sodium chlorite (43.7 g) in water (500 mL) was added slowly maintaining the temperature below 8° C. The reaction mixture was allowed to warm to room temperature. After 5 hours, the pH of the reaction was adjusted to 8 with a 6 N aqueous solution of sodium hydroxide (NaOH). The mixture was extracted with ethyl acetate (EtOAc). The aqueous layer was acidified to pH 4 with a 6N solution of hydrochloric acid (HCl) and extracted with dichloromethane (DCM). The combined DCM extracts were washed sequentially with 5% aqueous sodium sulfite and saturated brine, dried over sodium sulfate (Na2SO4) and concentrated under reduced pressure. The crude solid was triturated with methanol (MeOH) to give the title compound (17 g).

Workup

  1. temperaturemaintaining the temperature below 8° C
  2. extractionThe mixture was extracted with ethyl acetate (EtOAc)
  3. extractionextracted with dichloromethane (DCM)
  4. washThe combined DCM extracts were washed sequentially with 5% aqueous sodium sulfite and saturated brine
  5. dry with materialdried over sodium sulfate (Na2SO4)
  6. concentrationconcentrated under reduced pressure
  7. customThe crude solid was triturated with methanol (MeOH)

Sources & evidence

ORD record
ord-a57fbb4f4e11417b97ac166f083a7fdf
Source dataset
uspto-grants-2015_02
Patent number
US08962623B2

Reaction notes

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