Boron tribromide → HCID 178516668, compound

HRID 1248942Notes

Reaction equation

HRID 1248942 reaction equation
B(Br)(Br)Br.[F:5][C:6]1[CH:7]=[C:8]([CH:16]=[C:17]([F:21])[C:18]=1[O:19]C)[CH2:9][N:10]1[CH:14]=[N:13][N:12]=[C:11]1[SH:15]>C(Cl)Cl>[F:5][C:6]1[CH:7]=[C:8]([CH:16]=[C:17]([F:21])[C:18]=1[OH:19])[CH2:9][N:10]1[CH:14]=[N:13][N:12]=[C:11]1[SH:15]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 178493646HCID 178493646, compound

Product 1

HCID 178516668HCID 178516668, compoundYield 23%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
25 °C

Procedure

Boron tribromide (25.6 ml, 0.0408 mole) (40% BBr3 in methylene chloride) was added dropwise over 10 minutes to a suspension of 4-(3',5'-difluoro-4'-methoxybenzyl)-1,2,4-triazole-3-thiol, prepared as in Example 4, (3.3 g) in 50 ml methylene chloride and stirred overnight at 25° C. The reaction mixture was poured into a mixture of ice-ethyl acetate, separated, and extracted two additional times with ethyl acetate. The combined ethyl acetate extracts were washed with brine, dried with sodium sulfate, filtered, and evaporated to an oil. The oil was dissolved in methylene chloride:methanol (90:10) and purified on a flash silica column eluted with methylene chloride:methanol (90:10) to produce a solid which was recrystallized from ethanol-hexane to yield 0.8 g (23% ) of 4-(3',5'-difluoro-4'-hydroxybenzyl)-1,2,4-triazole-3-thiol, m.p.: 184°-185° C.

Workup

  1. customseparated
  2. extractionextracted two additional times with ethyl acetate
  3. washThe combined ethyl acetate extracts were washed with brine
  4. dry with materialdried with sodium sulfate
  5. filtrationfiltered
  6. customevaporated to an oil
  7. dissolutionThe oil was dissolved in methylene chloride:methanol (90:10)
  8. custompurified on a flash silica column
  9. washeluted with methylene chloride:methanol (90:10)
  10. customto produce a solid which
  11. customwas recrystallized from ethanol-hexane

Sources & evidence

ORD record
ord-f13027a43b574edc8f1c6152a9e4a018
Source dataset
uspto-grants-1986_12
Patent number
US04628059

Reaction notes

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