Acetic Anhydride → (4Z)-4-(4-Cyclopropylbenzylidene)-2-[4-(2-cyclopropylethoxy)phenyl]-1,3-oxazol-5(4H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of N-[4-(2-cyclopropylethoxy)benzoyl]glycine (184 mg, 0.699 mmol) prepared in Example 1 (1b), 4-cyclopropylbenzaldehyde (compound described in Tetrahedron Lett., (2002), 43, 6987-6990, 113 mg, 0.773 mmol), sodium acetate (75 mg, 0.914 mmol), and acetic anhydride (660 μL, 6.99 mmol) was stirred at 120° C. for 30 minutes and then allowed to cool to room temperature. The solidified product was ultrasonically washed with n-hexane (2 mL) and water (4 mL). Then, the precipitate was collected by filtration, washed with water and n-hexane, and dried by heating under reduced pressure to give 196 mg of the title compound (yellow powder, yield 74%). Hereinafter, the compound obtained by this cyclizing reaction is called oxazolone.

Provenance & Evidence