Boron tribromide → 4-[2-(3-Octyl-[1,2,4]oxadiazol-5-yl)-vinyl]-benzene-1,2-diol

HRID 470643Notes

Reaction equation

HRID 470643 reaction equation
B(Br)(Br)Br.C[O:6][C:7]1[CH:8]=[C:9]([CH:15]=[CH:16][C:17]2[O:21][N:20]=[C:19]([CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][CH3:29])[N:18]=2)[CH:10]=[CH:11][C:12]=1[O:13]C>ClCCl>[CH2:22]([C:19]1[N:18]=[C:17]([CH:16]=[CH:15][C:9]2[CH:8]=[C:7]([OH:6])[C:12]([OH:13])=[CH:11][CH:10]=2)[O:21][N:20]=1)[CH2:23][CH2:24][CH2:25][CH2:26][CH2:27][CH2:28][CH3:29]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 673980665-[2-(3,4-Dimethoxy-phenyl)-vinyl]-3-octyl-[1,2,4]oxadiazole2×

Product 1

HCID 1364132224-[2-(3-Octyl-[1,2,4]oxadiazol-5-yl)-vinyl]-benzene-1,2-diol

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a cooled solution of 0.997 mL of 1M boron tribromide (0.9 mmol) in 2 mL dichloromethane, 0.150 g (0.433 mmol) of 5-[2-(3,4-dimethoxy-phenyl)-vinyl]-3-octyl-[1,2,4]oxadiazole (compound of Example 48) 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 mass was further stirred at 25° C. to 30° C. for 4-5 h. After completion of the reaction, the reaction mixture was quenched in 10 mL of chilled 5% sodium bicarbonate solution, below 20° C. (pH: 8-9). 10 mL of ethyl acetate was added to the reaction mixture 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 mass was further stirred at 25° C. to 30° C. for 4-5 h
  5. customAfter completion of the reaction
  6. customthe reaction mixture was quenched in 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 mixture
  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-dc4043ab942145ff91c139cc36f3add7
Source dataset
uspto-grants-2014_01
Patent number
US08629277B2

Reaction notes

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