Acetic Acid → [(3-Methoxyphenyl)methylene]-2-methylquinolin-5-amine

Participants

Reaction Steps

To 1.17 g (7.4 mmol) 5-amino-2-methylquinolin and 1 g (7.4 mmol) 3-methoxybenzaldehyde in 39 ml toluene are added 1 ml acetic acid. The mixture is heated over 3 hours under reflux while water is trapped in a Dean Stark apparatus. The solvent is evaporated and the residue is two times azeotrophed with small portions of toluene. 2.1 g of [(3-methoxyphenyl)methylene]-2-methylquinolin-5-amine are obtained as product. 0.31 ml (3.6 mmol) 1,1,1-trifluoroepoxypropane in 17 ml THF and are cooled to −104° C. and 1.59 ml of a 2.5 M n-butyl lithium solution in hexane are added over 3 hours while the temperature does not exceed −99° C. 10 Minutes after complete addition 1.5 g (5.4 mmol) [(3-methoxyphenyl)methylene]-2-methylquinolin-5-amine in 5 ml THF are added over 0.5 hours while the temperature temperature does not exceed −99° C. After 0.5 hours at −100° C. 4 ml diethyl ether are added and the reaction mixture is warmed to 20° C. over one hour. The reaction was quenched by addition of saturated ammonium chloride solution. The phases were separated and the aqueous layer was extracted twice with diethyl ether, the combined organic phases washed with brine, dried over sodium sulphate and then evaporated. Flash chromatography on silica gel (aceton in hexane 30 to 40%) yields 800 mg of the desired epoxide.

Provenance & Evidence