4-Hydroxybenzoic acid hydrazide → 139521-50-9

HRID 892499Notes

Reaction equation

HRID 892499 reaction equation
[OH:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([NH:8][NH2:9])=[O:7])=[CH:4][CH:3]=1.[C:12](Cl)(=[O:22])[C:13]1[CH:21]=[CH:20][CH:19]=[C:15]([C:16](Cl)=O)[CH:14]=1>CC(N(C)C)=O>[C:13]1([C:12]2[O:22][C:6]([C:5]3[CH:10]=[CH:11][C:2]([OH:1])=[CH:3][CH:4]=3)=[N:8][N:9]=2)[CH:21]=[CH:20][CH:19]=[C:15]([C:16]2[O:7][C:6]([C:5]3[CH:10]=[CH:11][C:2]([OH:1])=[CH:3][CH:4]=3)=[N:8][N:9]=2)[CH:14]=1

Participants

4

Reactant 2

HCID 17424-Hydroxybenzoic acid hydrazideHCID 7451Isophthaloyl chloride2×

Product 1

HCID 136096151139521-50-9Yield 85%

Reagents, catalysts & solvents 1

HCID 31374DimethylacetamideSolvent2×

Conditions

Temperature
0 °C

Procedure

Into a 250 ml three neck round bottom flask equipped with a magnetic stirbar, thermometer, addition funnel, and glass stopper is placed 4-hydroxybenzoic hydrazide (6.0 g, 0.039 mol) and dry DMAc (90 ml). After the solid dissolves the solution is cooled to approximately 0° C. via an ice water bath. A solution of isophthaloyl chloride (4.0 g, 0.0195 mol) in dry DMAc (30 ml) is placed in the addition funnel. The isophthaloyl chloride solution is added dropwise over approximately one hour while maintaining the reaction temperature between 0° and 5° C. After the entire solution has been added, the ice bath is removed and the solution is allowed to warm to room temperature, stirring is continued for 16 hours. The DMAc solution is poured into ice/water to give a white precipitate which is collected by filtration and subsequently dried at 70° C. under vacuum. Yield 7.1 g (76%) of the intermediate dihydrazide, m.p. 298° C. (DTA). The intermediate dihydrazide (6.0 g) is placed in a vacuum oven and heated to 280° C. for approximately 4 hours to achieve cyclodehydration to the oxadiazole. The solid is pulverized and washed in hot ethanol to yield a yellow solid (4.3 g, 85%) m.p. greater than 400° C. The solid is used without further purification.

Workup

  1. additionthermometer, addition funnel
  2. dissolutionAfter the solid dissolves the solution
  3. temperaturewhile maintaining the reaction temperature between 0° and 5° C
  4. additionAfter the entire solution has been added
  5. customthe ice bath is removed
  6. temperatureto warm to room temperature
  7. additionThe DMAc solution is poured into ice/water
  8. customto give a white precipitate which
  9. filtrationis collected by filtration
  10. customsubsequently dried at 70° C. under vacuum
  11. temperatureheated to 280° C. for approximately 4 hours
  12. washwashed in hot ethanol

Sources & evidence

ORD record
ord-133c6584f9b143068c919e65da0befbf
Source dataset
uspto-grants-1992_06
Patent number
US05118781

Reaction notes

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