Sodium triacetoxyborohydride → 3-{2-[2-(4-Bromo-phenyl)-4-methyl-piperazin-1-yl]-ethyl}-pyrazolo[1,5-a]pyridine

HRID 1802777Notes

Reaction equation

HRID 1802777 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[NH:13][CH2:12][CH2:11][N:10]([CH3:14])[CH2:9]2)=[CH:4][CH:3]=1.[N:15]1[N:19]2[CH:20]=[CH:21][CH:22]=[CH:23][C:18]2=[C:17]([CH2:24][CH:25]=O)[CH:16]=1.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>O1CCCC1.C(OCC)(=O)C.C(O)(=O)C>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([CH:8]2[CH2:9][N:10]([CH3:14])[CH2:11][CH2:12][N:13]2[CH2:25][CH2:24][C:17]2[CH:16]=[N:15][N:19]3[CH:20]=[CH:21][CH:22]=[CH:23][C:18]=23)=[CH:6][CH:7]=1

Participants

7

Reactant 3

HCID 5049666Sodium triacetoxyborohydrideHCID 578992273-(4-Bromo-phenyl)-1-methyl-piperazineHCID 578992522-{Pyrazolo[1,5-a]pyridin-3-yl}acetaldehyde

Product 1

HCID 578992473-{2-[2-(4-Bromo-phenyl)-4-methyl-piperazin-1-yl]-ethyl}-pyrazolo[1,5-a]pyridineYield 50.2%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidCatalystHCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of 3-(4-bromo-phenyl)-1-methyl-piperazine (1.0 g, 3.92 mmol), pyrazolo[1,5-a]pyridin-3-yl-acetaldehyde (753 mg, 4.70 mmol) and acetic acid (1.2 mg) in tetrahydrofuran (15 mL) was added sodium triacetoxyborohydride (1.92 g, 8.62 mmol) and the resulting mixture was stirred at room temperature for 4 h. The reaction mixture was diluted with ethyl acetate, washed with a saturated aqueous sodium bicarbonate solution, a saturated aqueous solution of sodium chloride, dried over magnesium sulfate, filtered and concentrated in vacuo. Purification via flash silica gel column chromatography (heptane/ethyl acetate) gave 3-{2-[2-(4-bromo-phenyl)-4-methyl-piperazin-1-yl]-ethyl}-pyrazolo[1,5-a]pyridine (786 mg, 50% yield). LCMS (m/z): 401.00 (M+1).

Workup

  1. washwashed with a saturated aqueous sodium bicarbonate solution
  2. dry with materiala saturated aqueous solution of sodium chloride, dried over magnesium sulfate
  3. filtrationfiltered
  4. concentrationconcentrated in vacuo
  5. customPurification via flash silica gel column chromatography (heptane/ethyl acetate)

Sources & evidence

ORD record
ord-fc6399ecd6c049c9baadc29b2950b90b
Source dataset
uspto-grants-2013_01
Patent number
US08349883B2

Reaction notes

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