Triethylamine → N-[2-(2,4-Dimethoxyphenyl)heptyl]-N'-(2-t-butyl-5-carboxyphenyl)urea

Participants

Reaction Steps

A solution of 1.00 g (3.57 mmol) of 3-(2,4-dimethoxyphenyl)octanoic acid (prepared as described in Preparation 3), 982 mg (3.57 mmol) of diphenylphosphoryl azide and 361 mg (3.57 mmol) of triethylamine in 15 ml of benzene was heated under reflux for 2.5 hours. At the end of this time, the reaction temperature was allowed to reduce to room temperature, after which a solution of 739 mg (3.57 mmol) of 2-t-butyl-5-methoxycarbonylaniline (prepared as described in Preparation 5) in 10 ml of benzene was added t o the mixture, and the resulting mixture was heated under reflux for 2 hours and 45 minutes. The reaction mixture was cooled to room temperature, and then the mixture was diluted with ethyl acetate. The diluted solution was washed with 2 N aqueous hydrochloric acid, with water, with a saturated aqueous solution of sodium hydrogencarbonate and with a saturated aqueous solution of sodium chloride, in that order, after which it was dried over anhydrous magnesium sulfate. The solvent was then removed by distillation under reduced pressure, and the resulting residue was purified by column chromatography through 100 g of silica gel, using a 2:1 by volume mixture of ethyl acetate and hexane as the eluent, to give 728 mg of the desired urea derivative as a foam-like substance in a 42% yield. The derivative thus obtained was hydrolyzed in a similar manner to that described in Preparation 7 to give the title compound as a foam-like substance.

Provenance & Evidence