Ethyl Acetate → 8-Chloro-6-(2,4-dichlorophenyl)imidazo[1,2-a]pyrazine
Reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[C:9]1[NH:10][C:11](=O)[C:12]2[N:13]([CH:15]=[CH:16][N:17]=2)[CH:14]=1.C(=O)(O)[O-].[Na+].C(OCC)(=O)C.P(Cl)(Cl)([Cl:32])=O>>[Cl:32][C:11]1[C:12]2[N:13]([CH:15]=[CH:16][N:17]=2)[CH:14]=[C:9]([C:3]2[CH:4]=[CH:5][C:6]([Cl:8])=[CH:7][C:2]=2[Cl:1])[N:10]=1Participants
Procedure
650 mg (2.3 mmol) of 6-(2,4-dichlorophenyl)imidazo[1,2-a]pyrazin-8(7H)-one (Example 4A) were dissolved in 7 ml of phosphoryl chloride and stirred under reflux for 12 h. The reaction mixture was poured into 100 ml of saturated sodium bicarbonate solution, and solid sodium bicarbonate was added until a pH of 7 had been reached. Ethyl acetate was added, and the mixture was extracted. The organic phase was washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate and concentrated on a rotary evaporator. Methanol was added to the residue, and the precipitated solid was filtered off and washed with methanol and diethyl ether and dried under high vacuum. This gave 400 mg (58% of theory) of the product as a solid.
Workup
- temperatureunder reflux for 12 h
- additionwas added until a pH of 7
- extractionthe mixture was extracted
- washThe organic phase was washed with saturated aqueous sodium chloride solution
- dry with materialdried over magnesium sulfate
- concentrationconcentrated on a rotary evaporator
- additionMethanol was added to the residue
- filtrationthe precipitated solid was filtered off
- washwashed with methanol and diethyl ether
- customdried under high vacuum
Sources & evidence
- ORD record
- ord-20b7504545f046dc96ff1d943f97c29f
- Source dataset
- uspto-grants-2016_09
- Patent number
- US09434731B2
Reaction notes
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