1-Methyl-1H-pyrazole-4-carbaldehyde → 3'-Chloro-4-(1-methyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2']bipyrazine

HRID 220494

Reaction equation

HRID 220494 reaction equation
[Cl:1][C:2]1[C:3]([N:8]2[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]2)=[N:4][CH:5]=[CH:6][N:7]=1.[CH3:14][N:15]1[CH:19]=[C:18]([CH:20]=O)[CH:17]=[N:16]1.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>O1CCCC1>[Cl:1][C:2]1[C:3]([N:8]2[CH2:9][CH2:10][N:11]([CH2:20][C:18]3[CH:17]=[N:16][N:15]([CH3:14])[CH:19]=3)[CH2:12][CH2:13]2)=[N:4][CH:5]=[CH:6][N:7]=1

Participants

5

Reactant 3

HCID 5731171-Methyl-1H-pyrazole-4-carbaldehydeHCID 5049666Sodium triacetoxyborohydrideHCID 140864382-Chloro-3-(piperazin-1-yl)pyrazine

Product 1

HCID 866416573'-Chloro-4-(1-methyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2']bipyrazine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Dissolve 3′-chloro-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl (3.43 g, 17.3 mmol) in tetrahydrofuran (100 mL). Add 1-methyl-1H-pyrazole-4-carbaldehyde (2.244 g, 20.38 mmol) in dry tetrahydrofuran (5 mL), stir for 10 min. at room temperature, add sodium triacetoxyborohydride (4.32 g, 20.4 mmol) and subject the reaction to ultrasound stirring for 6 hr. at room temperature. Add saturated aqueous sodium hydrogen carbonate (100 mL) then 2 N sodium hydroxide (10 mL) to the mixture and extract with DCM (2×200 mL). Pass the combined DCM extracts through an IST Phase Separator Frit®, concentrate and purify (silica gel chromatography, eluting with 0:100 to 8:92 methanol:DCM), to give the title preparation as a crystalline solid (5.21 g, 92%). MS (ES): m/z=293.1 [M+H]+.

Workup

  1. customthe reaction
  2. customat room temperature
  3. extractionAdd saturated aqueous sodium hydrogen carbonate (100 mL) then 2 N sodium hydroxide (10 mL) to the mixture and extract with DCM (2×200 mL)
  4. concentrationconcentrate
  5. custompurify
  6. wash(silica gel chromatography, eluting with 0:100 to 8:92 methanol:DCM)
  7. customto give the title

Sources & evidence

ORD record
ord-cf81399f6b664e0cbccab945fd1dbf2c
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Linked notes

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