Dichloromethane → 5-Chloro-2-methyl-4-(o-tolyl)-2,4-dihydro[1,2,4]triazol-3-one

HRID 1106691Notes

Reaction equation

HRID 1106691 reaction equation
C[N:2](C)[NH:3][C:4]([NH:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1[CH3:13])=[O:5].Cl[C:16]([Cl:26])(OC(=O)OC(Cl)(Cl)Cl)Cl.[CH2:27](Cl)Cl>>[Cl:26][C:16]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=2[CH3:13])[C:4](=[O:5])[N:3]([CH3:27])[N:2]=1

Participants

4

Reactant 3

HCID 6344DichloromethaneHCID 94429TriphosgeneHCID 46125821,1-Dimethyl-4-(O-tolyl)semicarbazide

Product 1

HCID 187898205-Chloro-2-methyl-4-(o-tolyl)-2,4-dihydro[1,2,4]triazol-3-one

Procedure

To a solution of 11.1 g of the title compound of Step A dissolved in 600 mL methylene chloride under N2 was added 17.1 g of triphosgene. The solution was heated at reflux overnight, cooled, and then concentrated under reduced pressure. The resulting residue was dissolved in ethyl acetate and washed with water and then with saturated aqueous NaCl. The organic phase was dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by flash chromatography (30-50% ethyl acetate/hexanes as eluent) to afford 8.25 g of the title compound of Step B. 1H NMR (CDCl3): δ 7.42-7.30 (m,3H), 7.17 (d,1H), 3.54 (s,3H), 2.22(s,3H).

Workup

  1. temperatureThe solution was heated
  2. temperatureat reflux overnight
  3. temperaturecooled
  4. concentrationconcentrated under reduced pressure
  5. dissolutionThe resulting residue was dissolved in ethyl acetate
  6. washwashed with water
  7. dry with materialThe organic phase was dried (MgSO4)
  8. filtrationfiltered
  9. concentrationconcentrated under reduced pressure
  10. customThe residue was purified by flash chromatography (30-50% ethyl acetate/hexanes as eluent)

Sources & evidence

ORD record
ord-c39c64ef9d264f1ca9fa6528a1b6e591
Source dataset
uspto-grants-2000_05
Patent number
US06057352

Reaction notes

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