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

HRID 1601134Notes

Reaction equation

HRID 1601134 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-oneYield 64%

Procedure

To a solution of 11.1 g 2,2-dimethyl-N-(2-methylphenyl)hydrazine carboxamide dissolved in 600 mL methylene chloride under N2 was added 17.1 g triphosgene. The solution was heated at reflux overnight, cooled, then concentrated under reduced pressure. The resulting residue was dissolved in ethyl acetate and washed with water, then 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 (64%) 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-7dc389a57e3a4f1ab88b768e36d1bd34
Source dataset
uspto-grants-1999_11
Patent number
US05977149

Reaction notes

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