Acetic Acid → 3-[3,4-Bis(benzyloxy)-5-nitrophenyl]-5-methyl-1,2,4-oxadiazole
Reaction equation
[CH2:1]([O:8][C:9]1[CH:10]=[C:11]([CH:16]=[C:17]([N+:27]([O-:29])=[O:28])[C:18]=1[O:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)[C:12]([NH2:15])=[N:13][OH:14])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:30](O)(=O)[CH3:31]>CN(C)C=O.[Cl-].[Na+].O>[CH2:1]([O:8][C:9]1[CH:10]=[C:11]([C:12]2[N:15]=[C:30]([CH3:31])[O:14][N:13]=2)[CH:16]=[C:17]([N+:27]([O-:29])=[O:28])[C:18]=1[O:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
Procedure
To a stirred solution of 3,4-bis-benzyloxy-N′-hydroxy-5-nitro-benzamidine (1.0 g, 2.54 mmol) in dimethylformamide (5 mL) at room temperature was added 1,1-carbonyldiimidazole (0.494 g, 3.048 mmol) in one portion and the mixture was stirred at room temperature for ninety minutes. Thereupon, acetic acid (0.184 g, 3.067 mmol) was added dropwise and the mixture was allowed to stir for two hours at room temperature, then at 155° C. for three hours. The mixture was allowed to cool to room temperature, and poured onto ice-water (100 mL). Brine (10 mL) was added and the resulting precipitate was removed by filtration, washed with water and dried in air. The solid was then dissolved in dichloromethane (20 mL) and a spatula tip of activated charcoal was added. After stirring for twenty minutes, the suspension was filtered through celite and the filtrate was evaporated to leave a yellow oil that solidified on standing. After recrystallisation from dichloromethane/petroleum ether, 3-(3,4-bis-benzyloxy-5-nitrophenyl)-5-methyl-[1,2,4]oxadiazole was obtained as a pale yellow solid (0.537 g, 51%).
Workup
- stirringto stir for two hours at room temperature
- temperatureto cool to room temperature
- additionpoured onto ice-water (100 mL)
- customthe resulting precipitate was removed by filtration
- washwashed with water
- customdried in air
- dissolutionThe solid was then dissolved in dichloromethane (20 mL)
- additiona spatula tip of activated charcoal was added
- stirringAfter stirring for twenty minutes
- filtrationthe suspension was filtered through celite
- customthe filtrate was evaporated
- customto leave a yellow oil that solidified
- customAfter recrystallisation from dichloromethane/petroleum ether
Sources & evidence
- ORD record
- ord-1db894734b9b4ca6a78860fd3d53d971
- Source dataset
- uspto-grants-2014_12
- Patent number
- US08907099B2
Reaction notes
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