Potassium Carbonate → 2-(benzyloxy)-5-(6-bromopyridin-2-yl)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one

HRID 1396505Notes

Reaction equation

[CH2:1]([O:8][C:9]1[CH:18]=[C:12]2[C:13](=[O:17])[NH:14][CH2:15][CH2:16][N:11]2[N:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Br:19][C:20]1[CH:25]=[CH:24][CH:23]=[C:22](Br)[N:21]=1.CN(C)CCN.C([O-])([O-])=O.[K+].[K+]>C1(C)C=CC=CC=1.[Cu]I>[CH2:1]([O:8][C:9]1[CH:18]=[C:12]2[C:13](=[O:17])[N:14]([C:22]3[CH:23]=[CH:24][CH:25]=[C:20]([Br:19])[N:21]=3)[CH2:15][CH2:16][N:11]2[N:10]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

Conditions

Temperature: 120 °C

Procedure

Copper (I) iodide (0.047 g, 0.25 mmol) was added to a stirred suspension of 2-(benzyloxy)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one (0.3 g, 1.23 mmol), 2,6-dibromopyridine (0.58 g, 2.46 mmol), N,N-dimethylethylenediamine (0.08 mL, 0.74 mmol) and K2CO3 (0.34 g, 2.46 mmol) in toluene (12 mL). The reaction mixture was stirred at 120° C. for 48 hours. Then 2,6-dibromopyridine (0.146 g, 0.62 mmol), The solvent was evaporated in vacuo. The crude product was purified by flash column chromatography (silica; DCM). The desired fractions were collected, the solvents evaporated in vacuo and the residue triturated with pentane to yield 2-(benzyloxy)-5-(6-bromopyridin-2-yl)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one (0.20 g, 39% yield) as a pale yellow solid.

Workup

customThe crude product was purified by flash column chromatography (silica; DCM)
customThe desired fractions were collected
customthe solvents evaporated in vacuo
customthe residue triturated with pentane

Sources & evidence

ORD record: ord-39ff54f4adfe4d31a152b7e7e9ad8767
Source dataset: uspto-grants-2014_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08901125B2

Reaction notes

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