4-Piperidinecarboxylic acid → 5-methyl-2-piperidin-4-yl-1,3-benzoxazole
Reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([CH3:8])[CH:5]=[CH:4][C:3]=1[OH:9].[NH:10]1[CH2:15][CH2:14][CH:13]([C:16](O)=O)[CH2:12][CH2:11]1.[OH-].[K+]>O>[NH:10]1[CH2:15][CH2:14][CH:13]([C:16]2[O:9][C:3]3[CH:4]=[CH:5][C:6]([CH3:8])=[CH:7][C:2]=3[N:1]=2)[CH2:12][CH2:11]1Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 180 °C
Procedure
2-Amino-4-methylphenol (400 mg) and 4-piperidinecarboxylic acid (420 mg) were mixed with polyphosphoric acid (2 g) and stirred with heating at 180° C. for 2 hours. After cooling to room temperature, the reaction was stopped by adding water. The filtrate was adjusted to pH 12 with 50% potassium hydroxide aqueous solution and then extracted with methylene chloride. The organic layer was washed with saturated brine and dried with magnesium sulfate, and then the solvent was evaporated under a reduced pressure to obtain the title compound 2-(4-piperidyl)-5-methylbenzoxazole (586 mg).
Workup
- temperatureAfter cooling to room temperature
- extractionextracted with methylene chloride
- washThe organic layer was washed with saturated brine
- dry with materialdried with magnesium sulfate
- customthe solvent was evaporated under a reduced pressure
Sources & evidence
- ORD record
- ord-c4d53b28ba0d44e9a750eb549ad5a98a
- Source dataset
- uspto-grants-2001_10
- Patent number
- US06297246B1
Reaction notes
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