Water → 3-Phenyl-5-(2-thienyl)-1,2,4-oxadiazole

HRID 919362Notes

Reaction equation

HRID 919362 reaction equation
[C:1](=[N:9][OH:10])([NH2:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[OH-].[Na+].[S:13]1[CH:17]=[CH:16][CH:15]=[C:14]1[C:18](Cl)=O.O>CC(C)=O>[C:2]1([C:1]2[N:8]=[C:18]([C:14]3[S:13][CH:17]=[CH:16][CH:15]=3)[O:10][N:9]=2)[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 962WaterHCID 14798Sodium HydroxideHCID 69186N'-HydroxybenzenecarboximidamideHCID 789282-Thiophenecarbonyl chloride

Product 1

HCID 6956793-Phenyl-5-(2-thienyl)-1,2,4-oxadiazoleYield 82.8%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Conditions

Temperature
20 °C

Procedure

Benzamide oxime (5.00 g, 36.7 mmol) was dissolved in acetone (50 mL) at 0° C. The solution was stirred and 50% aqueous sodium hydroxide (4.5 mL) added. An exotherm was noted and a precipitate formed in the reaction mixture. The exotherm lasted for about 15 minutes and the slurry became thick. The solution was warmed to 20° C. and external cooling was added. The 2-thiophenecarbonyl chloride (5.36, 36.7 mmol) was added over 15 minutes maintaining the reaction mixture below 30° C. The reaction was maintained at 30° C. for 15 minutes and the slurry became thinner. The reaction mixture was cooled to room temperature and stirred for 20 additional minutes. Water (50 mL) was added and the resulting solids were stirred for 1 hour. The solids were collected by vacuum filtration, washed with water (2×50 mL) and dried on a Buchner funnel with air flow from vacuum overnight. 3-Phenyl-5-(2-thienyl)-1,2,4-oxadiazole (6.94 g, 30.4 mmol) was obtained as a white solid (83% yield).

Workup

  1. customa precipitate formed in the reaction mixture
  2. temperatureexternal cooling
  3. additionwas added
  4. temperaturemaintaining the reaction mixture below 30° C
  5. temperatureThe reaction was maintained at 30° C. for 15 minutes
  6. temperatureThe reaction mixture was cooled to room temperature
  7. stirringstirred for 20 additional minutes
  8. stirringthe resulting solids were stirred for 1 hour
  9. filtrationThe solids were collected by vacuum filtration
  10. washwashed with water (2×50 mL)
  11. customdried on a Buchner funnel with air flow from vacuum overnight

Sources & evidence

ORD record
ord-a296063028fe46078e5e6c3512a8a117
Source dataset
uspto-grants-2016_03
Patent number
US09273037B2

Reaction notes

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