Sodium hydride → 4-(4-Bromo-2-fluorobenzyl)-5-n-butyl-2-[2-chloro-5-(methoxycarbonyl)phenyl]-2,4-dihydro-3H-1,2,4-triazol-3-one

HRID 36284

Reaction equation

HRID 36284 reaction equation
[CH2:1]([C:5]1[NH:6][C:7](=[O:21])[N:8]([C:10]2[CH:15]=[C:14]([C:16]([O:18][CH3:19])=[O:17])[CH:13]=[CH:12][C:11]=2[Cl:20])[N:9]=1)[CH2:2][CH2:3][CH3:4].[H-].[Na+].[H][H].[Br:26][C:27]1[CH:34]=[CH:33][C:30]([CH2:31]Br)=[C:29]([F:35])[CH:28]=1>CN(C=O)C.O>[Br:26][C:27]1[CH:34]=[CH:33][C:30]([CH2:31][N:6]2[C:5]([CH2:1][CH2:2][CH2:3][CH3:4])=[N:9][N:8]([C:10]3[CH:15]=[C:14]([C:16]([O:18][CH3:19])=[O:17])[CH:13]=[CH:12][C:11]=3[Cl:20])[C:7]2=[O:21])=[C:29]([F:35])[CH:28]=1

Participants

7

Reactant 4

HCID 24758Sodium hydrideHCID 27336604-Bromo-2-fluorobenzyl bromideHCID 1357200825-n-Butyl-2-[2-chloro-5-(methoxycarbonyl)phenyl]-2,4-dihydro-3H-1,2,4-triazol-3-oneHCID 178418361HCID 178418361, compound

Product 1

HCID 100060494-(4-Bromo-2-fluorobenzyl)-5-n-butyl-2-[2-chloro-5-(methoxycarbonyl)phenyl]-2,4-dihydro-3H-1,2,4-triazol-3-oneYield 40%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent2×

Conditions

Temperature
50 °C

Procedure

A mixture of 789 mg (2.55 mmole) of 5-n-butyl-2-[2-chloro-5-(methoxycarbonyl)phenyl]-2,4-dihydro-3H-1,2,4-triazol-3-one (from Step C), 122.4 mg (3.06 mmole) of sodium hydride (60% in oil), and 2 mL of dry DMF was stirred at 50° C. for 2.5 hours, during which time hydrogen was evolved. A solution of 820 mg (3.06 mmole) of 4-bromo-2-fluorobenzyl bromide in DMF was added, and the mixture was stirred at 50° C. overnight. The cooled reaction mixture was diluted with H2O and extracted twice with ethyl acetate. The combined organic phase was washed with H2O and brine and then dried over Na2SO4. The filtered solution was concentrated, and the residue was flash chromatographed on 250 cc of silica gel packed in hexane (gradient elution with 6:1 to 5:1 hexane-EtOAc; some unreacted starting material was recovered by further elution with 95:5 CH2Cl2 --MeOH), yielding 503 mg (40%) of the title compound as an orange gum (TLC in 4:1 hexane-EtOAc), mass spectrum (FAB) m/e 496, 498 (M+1)+ .

Workup

  1. customThe cooled reaction mixture
  2. extractionextracted twice with ethyl acetate
  3. washThe combined organic phase was washed with H2O and brine
  4. dry with materialdried over Na2SO4
  5. concentrationThe filtered solution was concentrated
  6. customchromatographed on 250 cc of silica gel
  7. washgradient elution with 6:1 to 5:1 hexane-EtOAc
  8. customwas recovered by further elution with 95:5 CH2Cl2

Sources & evidence

ORD record
ord-bea94300c7df438382147d599c77b1a9
Source dataset
uspto-grants-1995_05
Patent number
US05411980

Linked notes

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