Toluene → Dimethyl [4-[2-(5-methyl-2-phenyl-4-oxazolyl)ethoxy]benzylidene]-malonate

Participants

Reaction Conditions

Reaction Steps

2-(5-Methyl-2-phenyl-4-oxazolyl)ethyl methanesulfonate obtained in Example 4 (compound [7]; 24.4 g) and dimethyl 2-(4-hydroxybenzylidene)malonate obtained in Preparation Example 1 (compound [8]; 20.5 g) were mixed with tetrabutylammonium bromide (1.4 g) and toluene (210 mL). The mixture was heated to 90° C. and dissolved. Then potassium carbonate (13.2 g) was added and the mixture was stirred at 110° C. for 6 hr. The reaction mixture was ice-cooled and water (210 mL) was added, which was followed by stirring. After standing still, the aqueous layer was removed and 10% aqueous sodium chloride solution (210 mL) was added to the organic layer with stirring. The reaction mixture was allowed to stand and the aqueous layer was removed. The organic layer was concentrated and the concentrated residue was dissolved in methanol (150 mL) under heating. The reaction mixture was cooled to 10° C. or less and the reaction mixture was stirred for 1 hr. The obtained crystals were collected by filtration and washed with methanol (65 mL) to give the title compound (compound [9]; 31.1 g, yield 85.0%).

Provenance & Evidence