Chlorodifluoromethane → Chloro Fluoro Triazolin-3-one

HRID 1292487Notes

Reaction equation

HRID 1292487 reaction equation
COCCOCCOCCOCCOC.[Cl:16][C:17]1[CH:22]=[CH:21][C:20]([N:23]2[C:27](=[O:28])[NH:26][C:25]([CH3:29])=[N:24]2)=[C:19]([F:30])[CH:18]=1.C(=O)([O-])[O-].[K+].[K+].Cl[CH:38]([F:40])[F:39].N1C=CN=N1>>[F:39][CH:38]([F:40])[N:26]1[C:27](=[O:28])[N:23]([C:20]2[CH:21]=[CH:22][C:17]([Cl:16])=[CH:18][C:19]=2[F:30])[N:24]=[C:25]1[CH3:29]

Participants

6

Reactant 5

HCID 6372Chlorodifluoromethane3×HCID 8925TetraglymeHCID 11430Potassium Carbonate3×HCID 1355016041-(4-chloro-2-fluorophenyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazoleHCID 178418936HCID 178418936, compound

Product 1

HCID 9882096Chloro Fluoro Triazolin-3-oneYield 251.4%

Conditions

Temperature
185 °C

Procedure

To a one liter resin flask equipped with a cold finger, mechanical stirrer, gas inlet tube, and a thermometer was added 333 mL of tetraglyme, followed by 50.0 grams (0.220 mole--1.0 equiv.) of 4,5-dihydro-1-(4-chloro-2-fluorophenyl)-3-methyl-5-oxo-1H-1,2,4-triazole (% wt/vol. triazole to solvent--15%). Under a nitrogen atmosphere and with stirring the mixture was warmed to 185° C., and 11.4 grams (0.082 mole--0.373 equiv.) of anhydrous potassium carbonate was added in one portion. To this was then added 7.1 grams (0.082 mole--0.373 equiv.) of gaseous chlorodifluoromethane below the surface of the reaction mixture. Upon completion of the addition the reaction mixture was stirred for about 10 minutes. The sequence of potassium carbonate and chlorodifluoromethane addition was then repeated three additional times for a total addition of 1.5 molar equivalents each of potassium carbonate and chlorodifluoromethane. Upon completion of the fourth set of additions the reaction mixture was held at 185° C. for about 15 minutes. After this time GC analysis of the reaction mixture indicated 100% conversion of the triazole starting material. After the reaction mixture was cooled to ambient temperature, the salt by-products were removed by filtration, and the filtrate was slowly poured into 1200 mL of water. The resultant slurry was stirred, and the solid was collected by filtration, washed with four 100 mL portions of water, and dried to a constant weight, yielding 57.3 grams of 90.6% pure 4-difluoromethyl-4,5-dihydro-1-(4-chloro-2-fluorophenyl)-3-methyl-5-oxo-1H-1,2,4-triazole (86.3% yield). GC analysis of the product indicated the presence of about 2.9% O-isomer by-product.

Workup

  1. customTo a one liter resin flask equipped with a cold finger, mechanical stirrer, gas inlet tube
  2. additionUpon completion of the addition the reaction mixture
  3. stirringwas stirred for about 10 minutes
  4. temperatureAfter the reaction mixture was cooled to ambient temperature
  5. customthe salt by-products were removed by filtration
  6. additionthe filtrate was slowly poured into 1200 mL of water
  7. stirringThe resultant slurry was stirred
  8. filtrationthe solid was collected by filtration
  9. washwashed with four 100 mL portions of water
  10. customdried to a constant weight

Sources & evidence

ORD record
ord-6259e4e99f7c47309fc14421baeee4a0
Source dataset
uspto-grants-1998_05
Patent number
US05756755

Reaction notes

Loading…