Sulfuric Acid → 2-(4-Chloro-2-fluoro-5-hydroxyphenyl)-4-methyl-5-(trifluoromethyl)-3(2H)-pyridazinone

HRID 1421623Notes

Reaction equation

HRID 1421623 reaction equation
[Cl:1][C:2]1[C:7]([OH:8])=[CH:6][C:5]([N:9]2[C:14](=[O:15])[C:13]([CH3:16])=[C:12]([C:17]([F:20])([F:19])[F:18])[C:11](C(OCC)=O)=[N:10]2)=[C:4]([F:26])[CH:3]=1.S(=O)(=O)(O)O>O>[Cl:1][C:2]1[C:7]([OH:8])=[CH:6][C:5]([N:9]2[C:14](=[O:15])[C:13]([CH3:16])=[C:12]([C:17]([F:19])([F:18])[F:20])[CH:11]=[N:10]2)=[C:4]([F:26])[CH:3]=1

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 18780172HCID 18780172, compound

Product 1

HCID 99490912-(4-Chloro-2-fluoro-5-hydroxyphenyl)-4-methyl-5-(trifluoromethyl)-3(2H)-pyridazinoneYield 51.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
130 °C

Procedure

A half gram (0.5 g) of 2-(4-chloro-2-fluoro-5-hydroxyphenyl)-6-ethoxycarbonyl-4-methyl-5-trifluoromethylpyridazin-3-one (the present compound 1-27) and 1.5 ml of a mixture of sulfuric acid and water (v/v=1/1) were mixed and heated for 5 hours on a 130° C. oil bath. The reaction solution was cooled to room temperature, allowed to stand at the same temperature overnight, and further heated for 8 hours on a 130° C. oil bath. The reaction solution was cooled to room temperature and poured into 50 ml of water. The precipitated crystals were filtered off, dissolved with 100 ml of ethyl acetate, dried over anhydrous magnesium sulfate and treated with active charcoal. The solvent was removed under reduced pressure to afford 0.21 g of 2-(4-chloro-2-fluoro-5-hydroxyphenyl)-4-methyl-5-trifluoromethylpyridazin-3-one (yield:51%).

Workup

  1. temperatureThe reaction solution was cooled to room temperature
  2. customto stand at the same temperature overnight
  3. temperaturefurther heated for 8 hours on a 130° C. oil bath
  4. temperatureThe reaction solution was cooled to room temperature
  5. filtrationThe precipitated crystals were filtered off
  6. dissolutiondissolved with 100 ml of ethyl acetate
  7. dry with materialdried over anhydrous magnesium sulfate
  8. additiontreated with active charcoal
  9. customThe solvent was removed under reduced pressure

Sources & evidence

ORD record
ord-e3b30d5c0e8e4a6f91f10668ba3fba03
Source dataset
uspto-grants-2000_06
Patent number
US06077953

Reaction notes

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