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

HRID 466051Notes

Reaction equation

HRID 466051 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-869fd573e8e845559aa86f1e8f73c7db
Source dataset
uspto-grants-1992_10
Patent number
US05155122

Reaction notes

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