Ethoxyquin → 2,2,4-Trimethyl-1,2-dihydro-6-quinolinol
Reaction equation
C([O:3][C:4]1[CH:5]=[C:6]2[C:11](=[CH:12][CH:13]=1)[NH:10][C:9]([CH3:15])([CH3:14])[CH:8]=[C:7]2[CH3:16])C.B(Br)(Br)Br>ClCCl>[CH3:14][C:9]1([CH3:15])[CH:8]=[C:7]([CH3:16])[C:6]2[C:11](=[CH:12][CH:13]=[C:4]([OH:3])[CH:5]=2)[NH:10]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A solution of 31 g of 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline in 300 mL of dichloromethane was treated with 30 mL of boron tribromide dropwise at −78° C. After the addition of boron tribromide, the cooling bath was removed and the reaction mixture was allowed to warm to room temperature. The resulting mixture was stirred at room temperature for 2 hours. The reaction mixture was then poured into crushed ice and the pH was adjusted to 9 with sodium bicarbonate. The product was the extracted into EtOAc. The organic solution was washed with water and brine, dried over magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by filtering through a short plug of silica gel eluting with 25% EtOAc in hexanes solution to give 12.4 g of 2,2,4-trimethyl-1,2-dihydroquinolin-6-ol as a light brown solid.