1,2-Dichloroethane → 4-(1-Ethyl-5-methyl-1h-pyrazol-4-ylmethyl)-3'-(4-fluoro-phenyl)-3,4,5,6-tetrahydro-2h-[1,2']bipyrazine hydrochloride

HRID 220515Notes

Reaction equation

HRID 220515 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:9]([N:14]3[CH2:19][CH2:18][NH:17][CH2:16][CH2:15]3)=[N:10][CH:11]=[CH:12][N:13]=2)=[CH:4][CH:3]=1.[CH2:20]([N:22]1[C:26]([CH3:27])=[C:25]([CH:28]=O)[CH:24]=[N:23]1)[CH3:21].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].[Cl:44]CCCl>>[ClH:44].[CH2:20]([N:22]1[C:26]([CH3:27])=[C:25]([CH2:28][N:17]2[CH2:16][CH2:15][N:14]([C:9]3[C:8]([C:5]4[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=4)=[N:13][CH:12]=[CH:11][N:10]=3)[CH2:19][CH2:18]2)[CH:24]=[N:23]1)[CH3:21]

Participants

5

Reactant 4

HCID 111,2-DichloroethaneHCID 5732041-Ethyl-5-methyl-1H-pyrazole-4-carbaldehydeHCID 5049666Sodium triacetoxyborohydrideHCID 673669592-(4-Fluorophenyl)-3-(piperazin-1-yl)pyrazine

Product 1

HCID 685947824-(1-Ethyl-5-methyl-1h-pyrazol-4-ylmethyl)-3'-(4-fluoro-phenyl)-3,4,5,6-tetrahydro-2h-[1,2']bipyrazine hydrochlorideYield 55%

Procedure

Dissolve 3′-(4-Fluoro-phenyl)-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl (0.183 g, 0.708 mmol) in DCE (8.5 mL). Add 1-ethyl-5-methyl-1H-pyrazole-4-carbaldehyde (0.117 g, 0.850 mmol) followed by sodium triacetoxyborohydride (0.225 g, 1.06 mmol) and stir at room temperature for 18 hr. Purify via SCX chromatography, followed by silica gel chromatography (eluting with 50:50 then 0:100 hexanes:ethyl acetate then 10:90 methanol:ethyl acetate), followed by reverse phase chromatography to give the free base of the title compound (149 mg, 55%). Dissolve the free base (0.138 g, 0.363 mmol) in methanol and add a solution of ammonium chloride (0.019 g, 0.363 mmol) in a minimal volume of methanol. Shake for 18 hr. at ambient temperature and concentrate to give 4-(1-Ethyl-5-methyl-1H-pyrazol-4-ylmethyl)-3′-(4-fluoro-phenyl)-3,4,5,6-tetrahydro-2H-[1,2′]bipyrazinyl hydrochloride (149 mg, 99%). MS (ES): m/z=381 [M+H]+.

Workup

  1. customPurify via SCX chromatography
  2. washeluting with 50:50

Sources & evidence

ORD record
ord-54569aaac5b94fe7b77b57ff927313d2
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Reaction notes

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