Tetrahydrofuran → Tert-butyl 4-(5-isobutyl-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylate

HRID 1045712Notes

Reaction equation

HRID 1045712 reaction equation
Br[C:2]1[N:7]2[CH:8]=[N:9][N:10]=[C:6]2[C:5]([N:11]2[CH2:16][CH2:15][N:14]([C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])[CH2:13][CH2:12]2)=[N:4][CH:3]=1.[Br-].[CH2:25]([Zn+])[CH:26]([CH3:28])[CH3:27].C1COCC1>Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1(C)C=CC=CC=1>[CH2:25]([C:2]1[N:7]2[CH:8]=[N:9][N:10]=[C:6]2[C:5]([N:11]2[CH2:16][CH2:15][N:14]([C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])[CH2:13][CH2:12]2)=[N:4][CH:3]=1)[CH:26]([CH3:28])[CH3:27]

Participants

6

Reactant 3

HCID 8028TetrahydrofuranHCID 58447004Tert-butyl 4-(5-bromo-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylateHCID 178448254HCID 178448254, compound

Product 1

HCID 67393909Tert-butyl 4-(5-isobutyl-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylateYield 64%

Reagents, catalysts & solvents 2

HCID 178418476HCID 178418476, compoundCatalystHCID 1140TolueneSolvent

Conditions

Temperature
20 °C

Procedure

A 50 mL round bottom flask was charged with tert-butyl 4-(5-bromo-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylate (0.5 g, 1.3 mmol), Pd(PPh3)2Cl2 (140.3 mg, 0.20 mmol) and toluene (8 mL) under N2. To the above was injected a 2 M solution of isobutylzinc(II) bromide in THF (10.4 mL, 5.2 mmol). The resulting mixture was stirred under N2 at 20° C. for 0.5 h then 100° C. overnight. Work-up: the reaction mixture was filtered. The filter cake was washed with EtOAc (10 mL) and the filtrate was extracted with more EtOAc (10 mL×3). The combined organic solutions were washed with brine, dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel with 2% methanol in dichloromethane, to afford 0.30 g (64%) of tert-butyl 4-(5-isobutyl-[1,2,4]triazolo[4,3-a]pyrazin-8-yl)piperazine-1-carboxylate as a yellow solid. MS m/z: 361 (M+H+).

Workup

  1. custom100° C. overnight
  2. filtrationthe reaction mixture was filtered
  3. washThe filter cake was washed with EtOAc (10 mL)
  4. extractionthe filtrate was extracted with more EtOAc (10 mL×3)
  5. washThe combined organic solutions were washed with brine
  6. dry with materialdried over anhydrous Na2SO4
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified by flash column chromatography on silica gel with 2% methanol in dichloromethane

Sources & evidence

ORD record
ord-d8e13b470dc04b8ca00a438668aa6b05
Source dataset
uspto-grants-2013_10
Patent number
US08569300B2

Reaction notes

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