Diphosgene → o-Hydroxyphenyl-1,3,4-oxadiazol-2-ol

HRID 34878

Reaction equation

HRID 34878 reaction equation
[C:1]([NH:10][NH2:11])(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[OH:4].Cl[C:13](OC(Cl)(Cl)Cl)=[O:14]>O1CCOCC1>[OH:4][C:3]1[CH:5]=[CH:6][CH:7]=[CH:8][C:2]=1[C:1]1[O:9][C:13](=[O:14])[NH:11][N:10]=1

Participants

4

Reactant 2

HCID 10426DiphosgeneHCID 13637Salicylic acid, hydrazide

Product 1

HCID 135624284o-Hydroxyphenyl-1,3,4-oxadiazol-2-olYield 76.9%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Conditions

Temperature
25 °C

Procedure

To a solution of 10 g of salicylhydrazide in 100 ml of p-dioxane was added dropwise 13.1 g of trichloromethyl chloroformate while maintaining the temperature at 20°-30° C. with external cooling. After stirring at 25° C. for 0.5 hours, the suspension was refluxed for 4 hours then cooled to 25° C. and poured into excess ice-water. The mixture was filtered and the residue was recrystallized from acetonitrile to yield 9.0 g of the subject compound; m.p. 198°-200° C.

Workup

  1. temperaturewhile maintaining the temperature at 20°-30° C. with external cooling
  2. temperaturethe suspension was refluxed for 4 hours
  3. temperaturethen cooled to 25° C.
  4. filtrationThe mixture was filtered
  5. customthe residue was recrystallized from acetonitrile

Sources & evidence

ORD record
ord-54e4549f7a4a49519e55eb80ab4cb91c
Source dataset
uspto-grants-1988_08
Patent number
US04764205

Linked notes

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