Boron tribromide → (4,4-Dimethyl-6-thiochromanoyloxy)benzoic acid

HRID 2050983Notes

Reaction equation

HRID 2050983 reaction equation
[CH3:1][C:2]1([CH3:31])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([C:12]([O:14]C3C=CC(C(OCC4C=CC=CC=4)=O)=CC=3)=[O:13])[CH:10]=2)[S:5][CH2:4][CH2:3]1.B(Br)(Br)Br>C(Cl)Cl>[CH3:1][C:2]1([CH3:31])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([C:12]([O:14][C:8]3[CH:7]=[CH:6][CH:11]=[CH:10][C:9]=3[C:12]([OH:14])=[O:13])=[O:13])[CH:10]=2)[S:5][CH2:4][CH2:3]1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 19834230Benzyl 4-(4,4-dimethyl-6-thiochromanoyloxy)benzoate

Product 1

HCID 19834232(4,4-Dimethyl-6-thiochromanoyloxy)benzoic acid

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-10 °C

Procedure

To a stirred solution of 580 mg (1.34) of benzyl 4-(4,4-dimethyl-6-thiochromanoyloxy)benzoate in 12 ml of methylene chloride at -10° C. under nitrogen was added slowly 1.24 ml of a 1.0M (1.24 mmol) solution of boron tribromide in methylene chloride. The reaction mixture was stirred at -10° C. for a further 2 h and then was quenched by the addition of ice. The organic layer was separated and the aqueous layer extracted with 2×25 ml methylene chloride. The organic extracts were combined and then washed with water and dried (MgSO4). The solution was then filtered and the solvent removed in-vacuo. The resultant residue was purified by flash chromatography (silica; 20% ethyl acetate in hexane followed by 100% ethyl acetate) and then recrystallization from a mixture of ethyl acetate and ethanol to give the title compound as a white solid. PMR (CDCl3): δ1.39 (6H, s), 2.10 (2H, m), 3.10 (2 H, m), 7.21 (1H, d, J~8.4 Hz), 7.28 (2H, d, J~8.7 Hz), 7.82 (1H, dd, J~8.4, 2.1 Hz), 8.14 (2H, d, J~8.7 Hz), 8.16 (1H, d, J~2.1 Hz).

Workup

  1. customwas quenched by the addition of ice
  2. customThe organic layer was separated
  3. extractionthe aqueous layer extracted with 2×25 ml methylene chloride
  4. washwashed with water
  5. dry with materialdried (MgSO4)
  6. filtrationThe solution was then filtered
  7. customthe solvent removed in-vacuo
  8. customThe resultant residue was purified by flash chromatography (silica; 20% ethyl acetate in hexane followed by 100% ethyl acetate)
  9. customrecrystallization
  10. additionfrom a mixture of ethyl acetate and ethanol

Sources & evidence

ORD record
ord-4669175e24524016be3f6ed8d70b3180
Source dataset
uspto-grants-1991_05
Patent number
US05015658

Reaction notes

Loading…