Boron tribromide → 1-(4-chloro-2-fluoro-5-hydroxyphenyl)-3-difluoromethyl-4,5-dihydro-4-methyl-1,2,4-triazol-5(1H)-one

HRID 2073685Notes

Reaction equation

HRID 2073685 reaction equation
[Cl:1][C:2]1[C:7]([O:8]C)=[CH:6][C:5]([N:10]2[C:14](=[O:15])[N:13]([CH3:16])[C:12]([CH:17]([F:19])[F:18])=[N:11]2)=[C:4]([F:20])[CH:3]=1.B(Br)(Br)Br>C(Cl)Cl>[Cl:1][C:2]1[C:7]([OH:8])=[CH:6][C:5]([N:10]2[C:14](=[O:15])[N:13]([CH3:16])[C:12]([CH:17]([F:18])[F:19])=[N:11]2)=[C:4]([F:20])[CH:3]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 148536521-(4-chloro-2-fluoro-5-methoxyphenyl)-3-difluoromethyl-4,5-dihydro-4-methyl-1,2,4-triazol-5(1H)-one

Product 1

HCID 148536531-(4-chloro-2-fluoro-5-hydroxyphenyl)-3-difluoromethyl-4,5-dihydro-4-methyl-1,2,4-triazol-5(1H)-oneYield 85.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a stirred ice cold solution of 1.5 g (0.0048 mole) of 1-(4-chloro-2-fluoro-5-methoxyphenyl)-3-difluoromethyl-4,5-dihydro-4-methyl-1,2,4-triazol-5(1H)-one in 80 mL of methylene chloride was added dropwise 14.2 mL of a 1M solution of boron tribromide in methylene chloride. After complete addition the mixture was allowed to warm to room temperature and stir for approximately 18 hours. The mixture was poured into ice water and the resultant mixture stirred until the ice had melted. The organic phase was separated from the mixture and was washed with two portions of water. After washing, the organic phase was dried over anhydrous magnesium sulfate and filtered. Evaporation of the filtrate under reduced pressure yielded 1.2 g of 1-(4-chloro-2-fluoro-5-hydroxyphenyl)-3-difluoromethyl-4,5-dihydro-4-methyl-1,2,4-triazol-5(1H)-one (mp 153°-155° C.), Compound 23.

Workup

  1. additionAfter complete addition the mixture
  2. customThe organic phase was separated from the mixture
  3. washwas washed with two portions of water
  4. washAfter washing
  5. dry with materialthe organic phase was dried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. customEvaporation of the filtrate under reduced pressure

Sources & evidence

ORD record
ord-20675d57fbbf4f339a9dbd6fc1a82d5f
Source dataset
uspto-grants-1990_04
Patent number
US04919708

Reaction notes

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