Propionic anhydride → 2-Ethyl-4H-pyrido[2,3-d][1,3]oxazin-4-one
Reaction equation
[NH2:1][C:2]1[N:10]=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[C:11](OC(=O)CC)(=O)[CH2:12][CH3:13]>>[CH2:12]([C:13]1[O:5][C:4](=[O:6])[C:3]2[CH:7]=[CH:8][CH:9]=[N:10][C:2]=2[N:1]=1)[CH3:11]Participants
3
Conditions
- Temperature
- 120 °C
Procedure
A suspension of 2-aminonicotinic acid (1.0 g 7.24 mmol) in propionic anhydride (10 mL) of was heated to 120° C. for 1 h under nitrogen atmosphere. The temperature was increased to 167° C. to remove the propionic acid and propionic anhydride under reduced pressure. The resulting brown solid was triturated with hexane and dried to give the title pyrido-oxazine (16) (1.10 g, 86%) as a white solid:
Workup
- temperatureThe temperature was increased to 167° C.
- customto remove the propionic acid and propionic anhydride under reduced pressure
- customThe resulting brown solid was triturated with hexane
- customdried
Sources & evidence
- ORD record
- ord-d55a1b3515774b9bbe935e0a33722329
- Source dataset
- uspto-grants-2003_04
- Patent number
- US06545005B1
Reaction notes
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