Dichloromethane → 4-[2-(Bromomethyl)phenyl]-2,4-dihydro-5-methoxy-2-methyl-3H-1,2,4-triazol-3-one

HRID 1601136Notes

Reaction equation

HRID 1601136 reaction equation
[CH3:1][O:2][C:3]1[N:4]([C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=2[CH3:16])[C:5](=[O:9])[N:6]([CH3:8])[N:7]=1.[Br:17]N1C(=O)CCC1=O.C(OOC(=O)C1C=CC=CC=1)(=O)C1C=CC=CC=1.C(Cl)Cl>C(Cl)(Cl)(Cl)Cl>[Br:17][CH2:16][C:11]1[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=1[N:4]1[C:3]([O:2][CH3:1])=[N:7][N:6]([CH3:8])[C:5]1=[O:9]

Participants

6

Reactant 4

HCID 6344DichloromethaneHCID 7187Benzoyl Peroxide2×HCID 67184N-bromobutanimide2×HCID 187898082,4-dihydro-5-methoxy-2-methyl-4-(2-methylphenyl)-3H-1,2,4-triazol-3-one

Product 1

HCID 110338324-[2-(Bromomethyl)phenyl]-2,4-dihydro-5-methoxy-2-methyl-3H-1,2,4-triazol-3-oneYield 34.2%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

To a solution/suspension of 6.7 g 2,4-dihydro-5-methoxy-2-methyl-4-(2-methylphenyl)-3H-1,2,4-triazol-3-one dissolved in 95 mL carbon tetrachloride under N2 was added N-bromosuccinimide (6.53 g) followed by a catalytic amount of benzoyl peroxide. The solution was heated at reflux for 2 h. Another 1.63 g N-bromosuccinimide and a catalytic amount of benzoyl peroxide were added and the solution was heated at reflux for an hour. After cooling, methylene chloride was added and the organic layer was washed successively with water, then 0.1 N sodium thiosulfate solution, then saturated aqueous NaCl. The combined organic extracts were dried (MgSO4), filtered, and concentrated under reduced pressure. The residue was purified by flash chromatography (3-10% diethylether/methylene chloride as eluent) to afford 3.12 g of the title compound of Step D. 1H NMR (CDCl3) δ 7.5 (m,1H), 7.44 (m,2H), 7.22 (m,1H), 4.60 (d,1H), 4.36 (d,1H), 3.96 (s,3H), 3.47 (s,3H).

Workup

  1. temperatureThe solution was heated
  2. temperatureat reflux for 2 h
  3. temperaturethe solution was heated
  4. temperatureat reflux for an hour
  5. temperatureAfter cooling
  6. washthe organic layer was washed successively with water
  7. dry with materialThe combined organic extracts were dried (MgSO4)
  8. filtrationfiltered
  9. concentrationconcentrated under reduced pressure
  10. customThe residue was purified by flash chromatography (3-10% diethylether/methylene chloride as eluent)

Sources & evidence

ORD record
ord-45ec2e839f0145b88fe090da8964b8d2
Source dataset
uspto-grants-1999_11
Patent number
US05977149

Reaction notes

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