Potassium Fluoride → HCID 86679971, compound

HRID 1915758Notes

Reaction equation

HRID 1915758 reaction equation
Cl[C:2]1[N:6]([CH3:7])[N:5]=[CH:4][C:3]=1[N+:8]([O-:10])=[O:9].[F-].[K+].[CH3:13][C@H:14]1[NH:19][CH2:18][CH2:17][N:16]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[CH2:15]1>CS(C)=O>[CH3:13][C@H:14]1[N:19]([C:2]2[N:6]([CH3:7])[N:5]=[CH:4][C:3]=2[N+:8]([O-:10])=[O:9])[CH2:18][CH2:17][N:16]([C:20]([O:22][C:23]([CH3:24])([CH3:26])[CH3:25])=[O:21])[CH2:15]1

Participants

5

Reactant 3

HCID 522689Potassium FluorideHCID 2756811(R)-1-Boc-3-methylpiperazineHCID 123448365-chloro-1-methyl-4-nitro-1H-pyrazole

Product 1

HCID 86679971HCID 86679971, compoundYield 87.6%

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of 5-chloro-1-methyl-4-nitro-1H-pyrazole from Example 1 (355 mg, 2.2 mmol) and potassium fluoride (511 mg, 8.8 mmol) in dry DMSO (20 mL) was added (R)-tert-butyl 3-methylpiperazine-1-carboxylate (507 mg, 2.53 mmol) and the mixture was heated in the microwave at 100° C. for 10 hr. The mixture was partitioned between water (40 mL) and EtOAc (100 mL) and the organic layer passed through a phase separation cartridge and concentrated under reduced pressure. Purification via silica gel column chromatography (0-100% EtOAc/isohexane) gave (R)-tert-butyl 3-methyl-4-(1-methyl-4-nitro-1H-pyrazol-5-yl)piperazine-1-carboxylate as an orange gum (627 mg). To a solution of this gum (179 mg, 0.55 mmol) and ammonium formate (256 mg, 4.4 mmol) in MeOH (10 mL) under nitrogen was added 10% palladium on carbon (59 mg, 0.55 mmol). The mixture was heated at 70° C. for 4 hr before being cooled, filtered and concentrated under reduced pressure. The residue was partitioned between water (20 mL) and DCM (60 mL) and the organic layer separated, passed through a phase separation cartridge and concentrated under reduced pressure to give (R)-tert-butyl 4-(4-amino-1-methyl-1H-pyrazol-5-yl)-3-methylpiperazine-1-carboxylate as a brown gum (150 mg, 80% over two steps). LCMS (ES+) m/z 296 (M+1).

Workup

  1. customThe mixture was partitioned between water (40 mL) and EtOAc (100 mL)
  2. customthe organic layer passed through a phase separation cartridge
  3. concentrationconcentrated under reduced pressure
  4. customPurification via silica gel column chromatography (0-100% EtOAc/isohexane)

Sources & evidence

ORD record
ord-4ca08d0913ce44748b57974ed03049f1
Source dataset
uspto-grants-2013_12
Patent number
US08614206B2

Reaction notes

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