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

HRID 549404Notes

Reaction equation

HRID 549404 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-422dd8c06bc54d549c487498bd006302
Source dataset
uspto-grants-2011_05
Patent number
US07943652B2

Reaction notes

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