Methyl Isocyanate → 5-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-2,4-dihydro-4-methyl-3H-1,2,4-triazol-3-one

HRID 1492998Notes

Reaction equation

HRID 1492998 reaction equation
[CH3:1][N:2]=[C:3]=[O:4].[CH3:5][C:6]([C:9]1[CH:10]=[C:11]([CH:16]=[C:17]([C:20]([CH3:23])([CH3:22])[CH3:21])[C:18]=1[OH:19])[C:12]([NH:14][NH2:15])=O)([CH3:8])[CH3:7].[OH-].[Na+]>C(O)C>[CH3:5][C:6]([C:9]1[CH:10]=[C:11]([C:12]2[N:2]([CH3:1])[C:3](=[O:4])[NH:15][N:14]=2)[CH:16]=[C:17]([C:20]([CH3:23])([CH3:22])[CH3:21])[C:18]=1[OH:19])([CH3:8])[CH3:7]

Participants

5

Reactant 3

HCID 12228Methyl IsocyanateHCID 14798Sodium HydroxideHCID 104229343,5-Di-tert-butyl-4-hydroxybenzohydrazide

Product 1

HCID 1355181725-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-2,4-dihydro-4-methyl-3H-1,2,4-triazol-3-oneYield 30%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Methyl isocyanate (1.02 g, 18 mmol) is added dropwise to a solution of the 3,5-bis(1,1-dimethylethyl)-4-hydroxybenzoic acid, hydrazide (2.35 g, 8.9 mmol) in absolute ethanol (100 ml). The reaction mixture is stirred at room temperature, concentrated, and poured into ice water. The precipitate (1.2 g) is collected by filtration and dissolved in two equivalents of 1N NaOH. The reaction mixture is refluxed for three hours, and then is cooled and neutralized. The product is extracted into ethyl acetate. Pure 5-[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]-2,4-dihydro-4-methyl-3H-1,2,4-triazol-3-one (0.8 g, 30%) is obtained by recrystallization from methanol, mp 308°-312° C.

Workup

  1. concentrationconcentrated
  2. additionpoured into ice water
  3. filtrationThe precipitate (1.2 g) is collected by filtration
  4. temperatureThe reaction mixture is refluxed for three hours
  5. temperatureis cooled
  6. extractionThe product is extracted into ethyl acetate

Sources & evidence

ORD record
ord-a59187c5a3d7452a9054c56cd4bd1c87
Source dataset
uspto-grants-1994_12
Patent number
US05376670

Reaction notes

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