Boron tribromide → HCID 136413221, compound

HRID 470640Notes

Reaction equation

HRID 470640 reaction equation
B(Br)(Br)Br.[CH:5]1([CH2:11][C:12]2[N:16]=[C:15]([CH:17]=[CH:18][C:19]3[CH:24]=[CH:23][C:22]([O:25]C)=[C:21]([O:27]C)[CH:20]=3)[O:14][N:13]=2)[CH2:10][CH2:9][CH2:8][CH2:7][CH2:6]1>ClCCl>[CH:5]1([CH2:11][C:12]2[N:16]=[C:15]([CH:17]=[CH:18][C:19]3[CH:20]=[C:21]([OH:27])[C:22]([OH:25])=[CH:23][CH:24]=3)[O:14][N:13]=2)[CH2:10][CH2:9][CH2:8][CH2:7][CH2:6]1

Participants

4

Procedure

To a cooled solution of 0.14 mL of 1M boron tribromide (1.5 mmol) in 2 mL dichloromethane, 0.216 g (0.658 mmol) of 3-cyclohexylmethyl-5-[2-(3,4-dimethoxy-phenyl)-vinyl]-[1,2,4]oxadiazole (compound of Example 45) dissolved in 1 mL of dichloromethane was added over a period of 15-20 min at −45° C. to −40° C. The reaction mixture was stirred at −45° C. to −40° C. for 30-45 min and allowed to attain 25° C. to 30° C. slowly, over a period of 1 h. The reaction mixture was further stirred at 25° C. to 30° C. for 4-5 h. After the completion of the reaction, the reaction mixture was quenched with 10 mL of chilled 5% sodium bicarbonate solution, below 20° C. (pH: 8-9). 10 mL of ethyl acetate was added to the reaction mass to dissolve the solid and stirred for 10-15 min. The organic layer was separated and the aqueous layer was washed with 10 mL of 10% sodium chloride solution. The organic layer was collected and distilled to obtain a crude residue, which was purified by column chromatography (silica gel, chloroform-methanol) to yield the title compound.

Workup

  1. additionwas added over a period of 15-20 min at −45° C. to −40° C
  2. customto attain 25° C. to 30° C.
  3. waitover a period of 1 h
  4. stirringThe reaction mixture was further stirred at 25° C. to 30° C. for 4-5 h
  5. customAfter the completion of the reaction
  6. customthe reaction mixture was quenched with 10 mL of chilled 5% sodium bicarbonate solution, below 20° C. (pH: 8-9)
  7. addition10 mL of ethyl acetate was added to the reaction mass
  8. dissolutionto dissolve the solid
  9. stirringstirred for 10-15 min
  10. customThe organic layer was separated
  11. washthe aqueous layer was washed with 10 mL of 10% sodium chloride solution
  12. customThe organic layer was collected
  13. distillationdistilled
  14. customto obtain a crude residue, which
  15. customwas purified by column chromatography (silica gel, chloroform-methanol)

Sources & evidence

ORD record
ord-71f4ec59bc09419bb5d390368d1c8f17
Source dataset
uspto-grants-2014_01
Patent number
US08629277B2

Reaction notes

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