Water → 5-[2-(3,4-Dimethoxy-phenyl)-vinyl]-3-propyl-[1,2,4]oxadiazole

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Reaction Steps

3-(3,4-Dimethoxy-phenyl)-acrylic acid (compound of Example 2, Method A, Step 1; 3.5 g, 16.80 mmol) was dissolved in dry DMF (35 mL). 1,1′-Carbonyldiimidazole (CDI) (3.0 g, 18.48 mmol) was added and the reaction mixture was stirred at room temperature. At the end of 3 h, N-hydroxy-butyramidine (1.88 g, 18.48 mmol) was added and the reaction mixture was stirred at room temperature for 8 h. After completion of the reaction, additional CDI (2.99 g, 18.48 mmol) was added and the reaction mixture was refluxed at 110° C. to 120° C. for 7 h to effect cyclodehydration. DMF was evaporated and the residue obtained was cooled to room temperature followed by addition of water (20 mL). The resulting mixture was extracted with ethyl acetate (3×15 mL). The combined organic layers were washed with water (2×10 mL) and brine (10 mL). The organic phase obtained was dried over anhydrous sodium sulfate and concentrated to afford the title compound.

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