Diisopropylethylamine → 5-Vinylpyrazin-2-amine
Reaction equation
[NH2:1][C:2]1[CH:7]=[N:6][C:5](Br)=[CH:4][N:3]=1.[CH:9](N(CC)C(C)C)(C)[CH3:10].[Cl-].[Li+].C([Sn](CCCC)(CCCC)CCCC)=C.[F-].[K+]>CN(C)C=O.C(Cl)Cl.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[NH2:1][C:2]1[CH:7]=[N:6][C:5]([CH:9]=[CH2:10])=[CH:4][N:3]=1Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 3
Conditions
- Temperature
- 120 °C
Procedure
A solution of 2-amino-5-bromopyrazine (500 mg, 2.87 mmol) in N,N-dimethylformamide (15 mL) was treated with tetrakis(triphenylphosphine)palladium(0) (66 mg, 0.06 mmol), N,N-diisopropylethylamine (1.25 mL, 7.18 mmol), lithium chloride (426 mg, 0.06 mmol), and vinyltri-n-butyltin (840 μL, 2.87 mmol), and the reaction was heated at 120° C. for 4 h. After such time, the reaction was cooled to 25° C., treated with a saturated aqueous potassium fluoride solution (10 mL), and stirred at 25° C. overnight for 16 h. The solution was then diluted with methylene chloride (25 mL) and extracted with methylene chloride (3×15 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Biotage chromatography (FLASH 40S, Silica, 2/3 to 1/4 hexanes/ethyl acetate) afforded 2-amino-5-vinylpyrazine (211 mg, 61%) as a light yellow solid: EI-HRMS m/e calcd for C6H7N3 (M+) 121.0640, found 121.0642.
Workup
- temperatureAfter such time, the reaction was cooled to 25° C.
- extractionextracted with methylene chloride (3×15 mL)
- dry with materialThe combined organic layers were dried over sodium sulfate
- filtrationfiltered
- concentrationconcentrated in vacuo
Sources & evidence
- ORD record
- ord-663568f7500244788720f64fadcb3245
- Source dataset
- uspto-grants-2006_11
- Patent number
- US07132425B2
Reaction notes
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