Hydrochloric Acid → 4-Ethyl-5-trifluoroacetamidobenzoxazole
Reaction equation
[NH2:1][C:2]1[C:7]([CH2:8][CH3:9])=[C:6]([NH:10][C:11](=[O:16])[C:12]([F:15])([F:14])[F:13])[CH:5]=[CH:4][C:3]=1[OH:17].Cl.[CH:19](OCC)(OCC)OCC>CO>[CH2:8]([C:7]1[C:2]2[N:1]=[CH:19][O:17][C:3]=2[CH:4]=[CH:5][C:6]=1[NH:10][C:11](=[O:16])[C:12]([F:13])([F:14])[F:15])[CH3:9]Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 90 °C
Procedure
A mixture of 2-amino-3-ethyl-4-trifluoroacetamidophenol (18.15 mmol) and concentrated hydrochloric acid (45 mL) in methanol (5.2 mL) is treated with triethyl orthoformate (27.2 mmol). A simple distillation apparatus is attached and the mixture is heated with an oil bath to 90° C. and methanol is distilled from the reaction. The reaction mixture is cooled to room temperature and distributed between ethyl ether (200 mL) and water (20 mL). The ether layer is washed with a 0.1 M aqueous solution of sodium hydroxide (20 mL), dried over magnesium sulfate and concentrated under reduced pressure to yield 4-ethyl-5-trifluoroacetamidobenzoxazole.
Workup
- distillationA simple distillation apparatus
- distillationmethanol is distilled from the reaction
- temperatureThe reaction mixture is cooled to room temperature
- washThe ether layer is washed with a 0.1 M aqueous solution of sodium hydroxide (20 mL)
- dry with materialdried over magnesium sulfate
- concentrationconcentrated under reduced pressure
Sources & evidence
- ORD record
- ord-486a62630e1d4fa9b831701849f7f973
- Source dataset
- uspto-grants-2000_08
- Patent number
- US06110952
Reaction notes
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