Sodium Bicarbonate → 3'-Chloro-4-(1,3,5-trimethyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2']bipyrazine

HRID 220549Notes

Reaction equation

HRID 220549 reaction equation
Cl.Cl.[Cl:3][C:4]1[C:5]([N:10]2[CH2:15][CH2:14][NH:13][CH2:12][CH2:11]2)=[N:6][CH:7]=[CH:8][N:9]=1.[CH3:16][N:17]1[C:21]([CH3:22])=[C:20]([CH:23]=O)[C:19]([CH3:25])=[N:18]1.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C(=O)([O-])O.[Na+]>O1CCCC1>[Cl:3][C:4]1[C:5]([N:10]2[CH2:11][CH2:12][N:13]([CH2:23][C:20]3[C:19]([CH3:25])=[N:18][N:17]([CH3:16])[C:21]=3[CH3:22])[CH2:14][CH2:15]2)=[N:6][CH:7]=[CH:8][N:9]=1

Participants

6

Reactant 4

HCID 516892Sodium BicarbonateHCID 7365151,3,5-trimethyl-1H-pyrazole-4-carboxaldehyde2×HCID 5049666Sodium triacetoxyborohydrideHCID 866416583'-chloro-3,4,5,6-tetrahydro-2H-[1,2']bipyrazinyl dihydrochloride

Product 1

HCID 866416593'-Chloro-4-(1,3,5-trimethyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2']bipyrazineYield 99%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a suspension of 3′-chloro-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl dihydrochloride (2.11 g, 7.77 mmol, 1 eq) in tetrahydrofuran (20 mL) add 1,3,5-trimethyl-1H-pyrazole-4-carbaldehyde (1.61 g, 11.65 mmol, 1.5 eq). Stir for 10 min and add sodium triacetoxyborohydride (4.20 g, 19.40 mmol, 2.5 eq) in one portion. Stir at room temperature under nitrogen for 1 hr., then add additional 1,3,5-trimethyl-1H-pyrazole-4-carbaldehyde (0.50 g, 3.6 mmol, 0.47 eq). Stir for 30 min., add saturated aq. sodium hydrogen carbonate (100 mL) slowly, and then extract with DCM (3×50 mL). Pass the combined DCM extracts through an IST Phase Separator Frit®, concentrate and purify (silica gel chromatography, eluting with 2:98 to 5:95 methanol:DCM), to give 3′-chloro-4-(1,3,5-trimethyl-1H-pyrazol-4-ylmethyl)-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl as a white powder (2.468 g, 98%). MS (ES): m/z=321 [M+H]+.

Workup

  1. stirringStir at room temperature under nitrogen for 1 hr
  2. stirringStir for 30 min.
  3. extractionextract with DCM (3×50 mL)
  4. concentrationconcentrate
  5. custompurify
  6. wash(silica gel chromatography, eluting with 2:98 to 5:95 methanol:DCM)

Sources & evidence

ORD record
ord-6d50b6a3c555464791c405d2e1c2dac2
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Reaction notes

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